Oxime ester photoinitiators with heteroaromatic groups

ABSTRACT

Compounds of the formulae (I), (II), (III) and (IV), wherein Ch 1  is e.g. the formula (V) or (VI); Ch 2  is the formula (VII) or (VIII); Het 1  is for example furyl, thienyl, pyrrolyl, pyridyl, benzothienyl, quinolyl or bithienyl; each of which is optionally substituted; Het 2  and Het 2 ′ e.g. are furylene, thienylene, pyrrolylene, benzothienylene, quinolylene, furylenecarbonyl, thienylenecarbonyl, benzothienylenecarbonyl or bithienylenecarbonyl; each of which is optionally substituted; A 1 , and Ar 1 ′ i.a. are phenyl, naphthyl, benzoyl or naphthoyl, each of which is optionally substituted; Ar 2  is for example phenylene, optionally substituted; M i.a. is C 1 -C 20 alkylene; R 1  is for example C 1 -C 12 alkyl or phenyl; R 2  and R 2 ′ for example are hydrogen or C 1 -C 20  alkyl; exhibit an unexpectedly good performance in photopolymerization reactions.

The invention pertains to new oxime ester compounds, having specificheteroaromatic substitutents, and their use as photoinitiators inphotopolymerizable compositions.

From U.S. Pat. No. 3,558,309 it is known that certain oxime esterderivatives are photoinitiators. In U.S. Pat. No. 4,255,513 oxime estercompounds are disclosed. EP 810595 discribes some oxime ester compoundshaving electron-donating groups. US-A-2001012596 describes aldoxime orketoxime ester compounds. From GB-A-2339571 and U.S. Pat. No. 6,485,885oxime ester compounds with OR—, SR— or NR₂-substituents as well ascorresponding photopolymerizable compositions, are known. U.S. Pat. No.4,202,697 discloses acrylamino-substituted oxime esters. In JP 7-140658A, Bull. Chem. Soc. Jpn. 1969, 42(10), 2981-3, Bull Chem. Soc. Jpn.1975, 48(8), 2393-4, Han'guk Somyu Konghakhoechi 1990, 27(9), 672-85,Macromolecules, 1991, 24(15), 4322-7 and European Polymer Journal, 1970,933-943 some aldoxime ester compounds are described.

In U.S. Pat. No. 4,590,145 and JP 61-24558-A several benzophenone oximeester compounds are disclosed. In Chemical Abstract No. 96:52526c, J.Chem. Eng. Data 9(3), 403-4 (1964), J. Chin. Chem. Soc. (Taipel) 41 (5)573-8, (1994), JP 62-273259-A (=Chemical Abstract 109:83463w), JP62-286961-A (=Derwent No. 88-025703104), JP 62-201859-A (=Derwent No.87-288481/41), JP 62-184056-A (=Derwent No. 87-266739/38), U.S. Pat. No.5,019,482 and J. of Photochemistry and Photobiology A 107, 261-269(1997) some p-alkoxy-phenyl oxime ester compounds are described.

In photopolymerization technology there still exists a need for highlyreactive, easy to prepare and easy to handle photoinitiators. Forexample, highly pigmented formulations are required for the high colorquality property in color filter resist applications. With the increaseof the pigment content, curing of color resists becomes more difficult.Hence, photoinitiators having higher sensitivity than the currentInitiation systems are required. In addition, such new photoinitiatorsmust meet the high requirements of the industry regarding propertieslike, for example, thermal stability and storage stability.

Surprisingly it was found, that compounds of the formulae I, II, III andIV

Het₁ is furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,oxazolyl, isoxazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, benzothiadiazolyl,2- or 3-indolyl, indazolyl, quinolyl, isoquinolyl, phthalazinyl,quinoxalinyl, pteridinyl, or bithienyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl;or each of which is substituted by phenyl or by phenyl which isoptionally substituted by one or more OR₃, SR₄ and/or NR₅R₆;or each of which is substituted by C₂-C₁₂alkoxycarbonyl, whichoptionally is interrupted by one or more —O— or —S— and saidC₂-C₁₂alkoxycarbonyl optionally is substituted by one or more hydroxylgroups;or each of which is substituted by one or more OR₃, SR₄, SOR₄, SO₂R₄and/or NR₅R₆, wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form5- or 6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ withfurther substituents on the heteroaromatic ring;or each of which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholinoand/or dimethylmorpholino;Het₂ and Het₂′ independently of one another are furylene, thienylene,pyrrolylene, imidazolylene, pyrazolylene, thiazolylene, oxazolylene,isoxazolylene, pyridylene, pyrazinylene, pyridazinylene, triazinylene,benzofurylene, benzothienylene, benzothiazolylene, benzothiadiazolylene,indolylene, indazolylen, quinolylene, isoquinolylene, phthalazinylene,quinoxalinylene, pteridinylene, bithienylene, furylenecarbonyl,thienylenecarbonyl, pyrrolylenecarbonyl, imidazolylenecarbonyl,pyrazolylene, thiazolylenecarbonyl, oxazolylenecarbonyl,pyridylenecarbonyl, pyrazinylenecarbonyl, pyridazinylenecarbonyl,triazinylenecarbonyl, benzofurylenecarbonyl, benzothienylenecarbonyl,benzothiazolylenecarbonyl, benzothiadiazolylenecarbonyl,indolylenecarbonyl, indazolylenecarbonyl, quinolylenecarbonyl,isoquinolylenecarbonyl, phthalazinylenecarbonyl,quinoxalinylenecarbonyl, pteridinylenecarbonyl or bithienylenecarbonyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆;or each of which is substituted by phenyl or by naphthyl, said phenyl ornaphthyl optionally is substituted by one or more OR₃, SR₄ and/or NR₅R₆,Ar₁ and Ar₁′ independently of one another are phenyl, naphthyl, benzoyl,naphthoyl, or a group

or

each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl;or each of which is substituted by phenyl or by phenyl which issubstituted by one or more OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino;or each of which is substituted by C₂-C₁₂alkoxycarbonyl which optionallyis interrupted by one or more —O— or —S— and/or optionally issubstituted by one or more hydroxyl groups;or each of which is substituted by one or more OR₃, SR₄, SOR₄, SO₂R₄NR₅R₆, morpholino and/or dimethylmorpholino;or each of which is substituted by C₁-C₈alkanoyl or benzoyl, saidC₁-C₈alkanoyl or benzoyl optionally is substituted by OR₃, SR₄, SOR₄,SO₂R₄, NR₅R₆, morpholino and/or dimethylmorpholino, wherein thesubstituents OR₃, SR₄ or NR₅R₈ optionally form 5- or 6-membered ringsvia the radicals R₃, R₄, R₅ and/or R₆ with further substituents on thephenyl ring;provided that(i) if in formula I, Ch₁ is

Ar₁′ is phenyl, Het₂ is 5-phenyl-4,3-isoxazolylene and R₂ is phenyl,then R₁ is not phenyl;Ar₂ is phenylene, naphthylene, phenylenecarbonyl, naphthylenecarbonyl,or a group

each of which is unsubstituted or substituted 1 to 6 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆;M is C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which is interrupted by one ormore —O— or —S—, said C₁-C₂₀alkylene and C₂-C₂₀alkylene optionally issubstituted by one or more halogen, OR₃, phenyl or phenyl substituted byOR₃, SR₄ and/or NR₅R₆;or M is phenylene or naphthylene, each of which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/orNR₅R₆;X is a direct bond, —O—, —S, —NR₅— or —CO—;Y is —O—, —S—, —NR₅—, —CO— or —CH₂—;R₁ is hydrogen, C₃-C₈cycloalkyl; or is C₁-C₁₂alkyl which isunsubstituted or substituted by one or more halogen, phenyl and/or CN;or R₁ is C₁-C₅alkenyl; or is phenyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ and/orNR₅R₆;or R₁ is C₁-C₈alkoxy, benzyloxy; or phenoxy which optionally issubstituted by one or more C₁-C₆alkyl and/or halogen;R₂ and R₂′ independently of each other are hydrogen; unsubstitutedC₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or more halogen, OR₃,phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₃-C₈cycloalkyl;or are C₂-C₂₀alkyl interrupted by one or more —O— or —S—, and/oroptionally substituted by one or more halogen, OR₃, phenyl and/or phenylsubstituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are phenyl which is unsubstituted or substituted by one ormore C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₂-C₂₀alkanoyl or benzoyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, phenyl, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₂-C₁₂alkoxycarbonyl optionally interrupted by one ormore —O— or —S— and/or optionally substituted by one or more hydroxylgroups;or R₂ and R₂′ are phenoxycarbonyl which is unsubstituted or substitutedby C₁-C₆alkyl, halogen, phenyl, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are CN, —CONR₅R₆, NO₂, C₁-C₄haloalkyl, S(O)_(m)—C₁-C₆alkylor S(O)_(m)-phenyl which is optionally substituted by C₁-C₁₂alkyl orSO₂—C₁-C₆alkyl;or R₂ and R₂′ are SO₂O-phenyl which optionally is substituted byC₁-C₁₂alkyl;or R₂ and R₂′ are furyl, thienyl, pyrrolyl or pyridyl;m is 1 or 2;R₃ is hydrogen, C₁-C₂₀alkyl or phenyl-C₁-C₃alkyl;or R₃ is C₁-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)—(C₁-C₄alkyl), —O(CO)phenyl, —(CO)OH and/or —(CO)O(C₁-C₄alkyl);or R₃ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—;or R₃ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl),C₁-C₈alkanoyl, C₂-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl;or R₃ is benzoyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, halogen, OH and/or C₁-C₄alkoxy;or R₃ is phenyl or naphthyl each of which is unsubstituted orsubstituted by halogen, OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/ordiphenylamino;n is 1-20;R₄ is hydrogen, C₁-C₂₀alkyl, C₂-C₁₂alkenyl, C₃-C₈cycloalkyl orphenyl-C₁-C₃alkyl;or R₄ is C₁-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl);or R₄ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—;or R₄ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl),C₁-C₈alkanoyl, C₂-C₁₂alkenyl or C₃-C₆alkenoyl;or R₄ is benzoyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, halogen, OH, C₁-C₄alkoxy or C₁-C₄alkylsulfanyl;or R₄ is phenyl or naphthyl, each of which is unsubstituted orsubstituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenyl-C₁-C₃alkyloxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂,diphenylamino, —(CO)O(C₁-C₈alkyl), —(CO)—C₁-C₈alkyl or(CO)N(C₁-C₈alkyl)₂; andR₅ and R₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁₀alkoxyalkyl, C₂-C₅alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl, C₁-C₈alkanoyl, C₃-C₁₂-alkenoyl or benzoyl;or R₅ and R₆ are phenyl or naphthyl, each of which is unsubstituted orsubstituted by C₁-C₁₂alkyl, benzoyl or C₁-C₁₂alkoxy;or R₅ and R₆ together are C₂-C₈alkylene which optionally is interruptedby —O—, —S— or —NR₃— and/or optionally substituted by hydroxyl,C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy; exhibit an unexpectedlygood performance in photopolymerization reactions compared with thephotoinitiator individual structures or the mixtures thereof on whichthey are based.

Substituted aryl or arylene radicals Ar₁, Ar₁′, Ar₂, Het₁, Het₂, Het₂′or M are substituted 1 to 7, 1 to 6 or 1 to 4 times respectively. It isevident that a defined aryl radical cannot have more substituents thanfree positions at the aryl ring. The radicals are substituted 1 to 7times, for example 1 to 6 times or 1 to 4 times, in particular one, twoor three times.

Substituted radicals phenyl, are for example, substituted one to 4times, for example one, two or three times, especially two times.Substituents on the phenyl ring are preferably in positions 4 or in3,4-, 3,4,5-, 2,6-, 2,4- or 2,4,6-configuration on the phenyl ring.

Naphthyl is 1-naphthyl or 2-naphthyl.

Naphthoyl is 1-naphthoyl or 2-naphthoyl.

The heteroaryl groups which are given as definitions for Het₁, Het₂ andHet₂′ are known to the person killed in the art. If no specificpositions are indicated in the claims, in the context of thisapplication all possible positions are meant, for the radical “yl” (i.e.the bond to the rest of the molecule), as well as for the position ofthe heteroatoms in the rings.

Furyl is

furylene means

furylenecarbonyl constitutes

Thienyl is

e.g. 2-thienyl

or 3-thienyl

thienylene means

thienylenecarbonyl constitutes

Analogous considerations concerning the definitions and positions of thebonds apply for the other named heteroaryl groups.

C₁-C₂₀alkyl is linear or branched and is, for example, C₁-C₁₈—, C₁-C₁₄—,C₁-C₁₂—, C₁-C₈—, C₁-C₆— or C₁-C₄alkyl or C₄-C₁₂— or C₄-C₈alkyl. Examplesare methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl,tert-butyl, pentyl, hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl,octyl, nonyl, decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl,octadecyl and icosyl. C₁-C₁₂alkyl, C₂-C₁₂alkyl, C₁-C₁₁alkyl, C₁-C₈alkyland C₁-C₆alkyl have the same meanings as given above for C₁-C₂₀alkyl upto the corresponding number of C-atoms.

C₂-C₂₀alkyl which is interrupted by one or more —O— or is for exampleinterrupted 1-9, 1-5, 1-3 or once or twice by —O— or ——S. The —O-atomsare non-consecutive. For example, two O-atoms are separated by at leasttwo methylene groups, namely ethylene. The alkyl groups are linear orbranched. For example the following structural units will occur,—CH₂—CH₂—O—CH₂CH₃, —[CH₂CH₂O]_(y)—CH₃, wherein y=1-9,—(CH₂—CH₂O)₇—CH₂CH₃, —CH₂—CH(CH₃)—O—CH₂—CH₂CH₃ or —CH₂—CH(CH₃)—O—CH₂—CH₃or —CH₂—CH₂—S—CH₂CH₃, —[CH₂CH₂S]_(y)—CH₃, wherein y=1-9,—(CH₂—CH₂S)₇—CH₂CH₃, —CH₂—CH(CH₃)—S—CH₂—CH₂CH₃ or —CH₂—CH(CH₃)—S—CH₂CH₃.

C₁-C₂₀alkylene is linear or branched and is, for example, C₁-C₁₆—,C₁-C₁₂—, C₁-C₁₀—, C₁-C₈—, C₁-C₆— or C₁-C₄alkylene or C₄-C₁₂— orC₄-C₈alkylene. Examples are methylene, ethylene, propylene,methylethylene, butylene, methylpropylene, ethylethylene,1,1-dimethylethylene, 1,2-dimethylethylene, pentylene, hexylene,heptylene, 2-ethylhexylene, octylene, nonylene, decylene, dodecylene,tetradecylene, pentadecylene, hexadecylene, octadecylene and icosylene.C₁-C₁₀alkylene has the same meanings as given above for C₁-C₂₀alkyleneup to the corresponding number of C-atoms.

C₂-C₄hydroxyalkyl means C₂-C₄alkyl, which substituted by one or twoO-atoms. The alkyl radical is linear or branched. Examples are2-hydroxyethyl, 1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl,3-hydroxypropyl, 1-hydroxybutyl, 4-hydroxybutyl, 2-hydroxybutyl,3-hydroxybutyl, 2,3-dihydroxypropyl, or 2,4-dihydroxybutyl.

C₃-C₈cycloalkyl is for example cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cyclooctyl, especially cyclopentyl and cyclohexyl.

C₁-C₁₂alkoxy is C₁-C₁₂alkyl, which is substituted by one-O-atom.C₁-C₁₂alkyl has the same meanings as given above for C₁-C₂₀alkyl up tothe corresponding number of C-atoms. C₁-C₄alkoxy is linear or branched,for example, methoxy, ethoxy, propoxy, isopropoxy, n-butyloxy,sec-butyloxy, isobutyloxy, tert-butyloxy.

C₁-C₁₂alkylsulfanyl is C₁-C₁₂alkyl, which is substituted by ones-atom.C₁-C₁₂alkyl has the same meanings as given above for C₁-C₂₀alkyl up tothe corresponding number of C-atoms. C₁-C₄alkylsulfanyl is linear orbranched, for example, methylsulfanyl, ethylsulfanyl, propylsulfanyl,isopropylsulfanyl, n-butylsulfanyl, sec-butylsulfanyl, isobutylsulfanyl,tert-butylsulfanyl.

C₂-C₁₀alkoxyalkyl is C₂-C₁₀alkyl, which is interrupted by one O-atom.C₂-C₁₀alkyl has the same meanings as given above for C₁-C₂₀alkyl up tothe corresponding number of C-atoms. Examples are methoxymethyl,methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl,porpoxymethyl, prpopxyethyl, propoxypropyl.

C₂-C₂₀alkanoyl is linear or branched and is, for example, C₂-C₁₈—,C₂-C₁₄—, C₂-C₁₂, C₂-C₈—, C₂-C₆— or C₂-C₄alkanoyl or C₄-C₁₂- orC₄-C₈alkanoyl. Examples are acetyl, propionyl, butanoyl, isobutanoyl,pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl,dodecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, octadecanoyl,icosanoyl, preferably acetyl. C₁-C₈alkanoyl has the same meanings asgiven above for C₂-C₂₀alkanoyl up to the corresponding number ofC-atoms.

C₂-C₄alkanoyloxy is linear or branched, for example acetyloxy,propionyloxy, butanoyloxy, isobutanoyloxy, preferably acetyloxy.

C₂-C₁₂alkoxycarbonyl is a linear or branched and is, for example,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, n-butyloxycarbonyl,isobutyloxycarbonyl, 1,1-dimeth-ylpropoxycarbonyl, pentyloxycarbonyl,hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl, nonyloxycarbonyl,decyloxycarbonyl or dodecyloxycarbonyl, especially methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, n-butyloxycarbonyl oriso-butyloxycarbonyl, preferably methoxycarbonyl.

C₂-C₁₂alkoxycarbonyl which is interrupted by one or more —O— or —S— islinear or branched. Two O-atoms are separated by at least two methylenegroups, namely ethylene.

Phenoxycarbonyl is

Substituted phenoxycarbonyl radicals are substituted one to four times,for example one, two or three times, especially two or three times.Substituents on the phenyl ring are preferably in positions 4 or in3,4-, 3,4,5-, 2,6-, 2,4- or 2,4,6-position on the phenyl ring, inparticular in 4- or 3,4-position.

Phenyl-C₁-C₃alkyl is for example benzyl, phenylethyl, α-methylbenzyl orα,α-dimethylbenzyl, especially benzyl.

C₂-C₁₂alkenyl radicals may be mono- or polyunsaturated and are forexample vinyl, allyl, methallyl, 1,1-dimethylallyl, 1-butenyl,3-butenyl, 2-butenyl, 1,3-pentadienyl, 5-hexenyl, 7-octenyl ordodecenyl, especially allyl. C₂-C₅alkenyl radicals have the samemeanings as given above for C₂-C₁₂alkenyl radicals up to thecorresponding number of C-atoms.

C₃-C₆alkenoxy radicals may be mono- or polyunsaturated and are forexample allyloxy, methallyloxy, butenyloxy, pentenoxy,1,3-pentadienyloxy, 5-hexenyloxy.

C₃-C₁₂alkenoyl radicals may be mono- or polyunsaturated and are forexample propenoyl, 2-methyl-propenoyl, butenoyl, pentenoyl,1,3-pentadienoyl, 5-hexenoyl. C₃-C₆alkenoyl radicals have the samemeanings as given above for C₃-C₁₂alkenoyl radicals up to thecorresponding number of C-atoms.

Halogen is fluorine, chlorine, bromine and iodine, especially fluorine,chlorine and bromine, preferably fluorine and chlorine.

If the substituents OR₃, SR₄ and NR₅R₆ on a heteroaryl (e.g. Het₁), aryl(e.g. Ar₁, Ar₁′) ring form 5- or 6-membered rings via the radicals R₃,R₄, R₅ and/or R₆ with further substituents on the corresponding ring,structures comprising two or three rings (inclusive the correspondingring) are obtained. Examples are

It is clear, that in the context of the present definitions and in viewof the examples these groups may bear further substituents.

Oxime esters of formulae I, II, III and IV are prepared by methodsdescribed in the literature, for example by reaction of thecorresponding oximes with an acyl chloride or an anhydride in an inertsolvent such as for example t-Butyl methyl ether, tetrahydrofuran (THF)or dimethylformamide in the presence of a base, for exampletriethylamine or pyridine, or in a basic solvent such as pyridine.

Such reactions are well known to those skilled in the art, and aregenerally carried out at temperatures of −15 to +50° C., preferably 0 to25° C.

The compounds of formulae II, III and IV can be obtained analogously byusing the appropriate oximes as starting materials:

Ch₁, Ch₂, Ar₁, M, R₂ and R₂′ have the meanings as given above.

The oximes required as starting materials can be obtained by a varietyof methods described in standard chemistry textbooks (for instance in J.March, Advanced Organic Chemistry, 4th Edition, Wiley Interscience,1992), or in specialized monographs, for example, S. R. Sandler & W.Karo, Organic functional group preparations, Vol. 3, Academic Press.

One of the most convenient methods is, for example, the reaction ofaldehydes or ketones with hydroxylamine or its salt in polar solventslike ethanol or aqueous ethanol. In that case, a base such as sodiumacetate or pyridine is added to control the pH of the reaction mixture.It is well known that the rate of the reaction is pH-dependent, and thebase can be added at the beginning or continuously during the reaction.Basic solvents such as pyridine can also be used as base and/or solventor cosolvent. The reaction temperature is generally the refluxingtemperature of the mixture, usually about 60-120° C.

Another convenient synthesis of oximes is the nitrosation of “active”methylene groups with nitrous add or an alkyl nitrite. Both alkalineconditions, as described for example in Organic Syntheses coll. Vol. VI(J. Wiley & Sons, New York, 1988), pp 199 and 840, and acidicconditions, as described, for example, in Organic Synthesis coll. vol V,pp 32 and 373, coll. vol. III, pp 191 and 513, coll. vol. II, pp. 202,204 and 363, are suitable for the preparation of the oximes used asstarting materials in the invention. Nitrous acid is usually generatedfrom sodium nitrite. The alkyl nitrite can be for example methylnitrite, ethyl nitrite, isopropyl nitrite, butyl nitrite, or isoamylnitrite.

Every oxime ester group can exist in two configurations, (Z) or (E). Itis possible to separate the isomers by conventional methods, but it isalso possible to use the isomeric mixture as such as photoinitiatingspecies. Therefore, the invention also relates to mixtures ofconfigurational isomers of compounds of the formulae I, II, III and IV.

Preferred compounds of formula I, II, III and IV are such, wherein

Het₁ is furyl thienyl, pyrrolyl, pyridyl, pyrazinyl, pyridazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, 2- or 3-indolyl,quinolyl, isoquinolyl or quinoxalinyl; each of which is unsubstituted orsubstituted 1 to 7 times by halogen or C₁-C₁₂alkyl;

or each of which is substituted by phenyl or by phenyl which optionallyis substituted by one or more OR₃, SR₄ and/or NR₅R₆;

or each of which is substituted by OR₃, SR₄, SOR₄ and/or NR₅R₆, whereinthe substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-memberedrings via the radicals R₃, R₄, R₅ and/or R₆ with further substituents onthe heteroaromatic ring;

or each of which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino;

Het₂ and Het₂′ independently of one another are furylene, thienylene,pyrrolylene, benzofurylene, benzothienylene, indolylene, quinolylene,isoquinolylene, quinoxalinylene, furylenecarbonyl, thienylenecarbonyl,pyrrolylenecarbonyl, benzofurylenecarbonyl, benzothienylenecarbonyl,indolylenecarbonyl, quinolylenecarbonyl, isoquinolylenecarbonyl,quinoxalinylenecarbonyl; each of which is unsubstituted or substituted 1to 7 times by halogen, C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄,SOR₄, SO₂R₄ and/or NR₅R₆;

or each of which is substituted by phenyl or naphthyl, said phenyl ornaphthyl optionally is substituted by one or more OR₃, SR₄ and/or NR₅R₆;

Ar₁ and Ar₁′ independently of one another are phenyl, naphthyl or agroup (B);

each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₆alkyl, OR₃, SR₄, NR₅R₆, morpholino and/or dimethylmorpholino,

or each of which is substituted by benzoyl, phenyl or by phenyl which isoptionally substituted by one or more OR₃, SR₄, SOR₄, NR₅R₆, morpholinoand/or dimethylmorpholino;

Ar₂ is phenylene, naphthylene, phenylenecarbonyl, naphthylenecarbonyl,or a group (C), (D), (E) or (F),

each of which is unsubstituted or substituted 1 to 6 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆;

M is C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which is interrupted by one ormore —O— or —S—, said C₁-C₂₀alkylene and C₂-C₂₀alkylene optionally issubstituted by one or more halogen, OR₃, phenyl or phenyl substituted byOR₃, SR₄ and/or NR₅R₆;

-   -   or M is phenylene or naphthylene, each of which is unsubstituted        or substituted by one or more C₁-C₆alkyl, phenyl, halogen, OR₃,        SR₄ and/or NR₅R₆;        X is a direct bond or —CO—,        Y is —O—, —S— or —NR₅—;        R₁ is C₁-C₆alkyl which is unsubstituted or substituted by one or        more halogen or phenyl;        or R₁ is phenyl which is unsubstituted or substituted by one or        more C₁-C₆alkyl, halogen, OR₃, SR₄ and/or NR₅R₆;        or R₁ is C₁-C₈alkoxy or benzyloxy;        R₂ and R₂′ independently of each other are hydrogen;        unsubstituted C₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or        more halogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄        and/or NR₅R₆;        or R₂ and R₂′ are C₃-C₈cycloalkyl; or are C₂-C₂₀alkyl        interrupted by one or more —O— and/or optionally substituted by        one or more halogen, OR₃, phenyl and/or phenyl substituted by        OR₃, SR₄ and/or NR₅R₆;        or R₂ and R₂′ are phenyl which is unsubstituted or substituted        by one or more C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or        NR₅R₆;        or R₂ and R₂′ are C₂-C₂₀alkanoyl or benzoyl which is        unsubstituted or substituted by one or more C₁-C₆alkyl, phenyl,        OR₃, SR₄ and/or NR₅R₆;        or R₂ and R₂′ are furyl, thienyl, pyrrolyl or pyridyl;        R₃ is hydrogen, C₁-C₂₀alkyl or phenyl-C₁-C₃alkyl;        or R₃ is C₁-C₈alkyl which is substituted by C₃-C₆alkenoxy,        —O(CO)—(C₁-C₄alkyl) or —O(CO)phenyl;        or R₃ is C₂-C₁₂alkyl which is interrupted by one or more —O—,        or R₃ is C₁-C₈alkanoyl or is benzoyl which is unsubstituted or        substituted by one or more C₁-C₆alkyl, halogen and/or        C₁-C₄alkoxy;        or R₃ is phenyl or naphthyl each of which is unsubstituted or        substituted by halogen, C₁-C₁₂alkyl, C₁-C₄alkoxy,        C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/or        diphenylamino;

-   R₄ is hydrogen, C₁-C₂₀alkyl, or is C₁-C₈alkyl which is substituted    by —O(CO)—(C₁-C₄alkyl) or —O(CO)-phenyl;    or R₄ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—;    or R₄ is C₁-C₈alkanoyl; or is benzoyl which is unsubstituted or    substituted by one or more C₁-C₆alkyl, C₁-C₄alkoxy or    C₁-C₄alkylsulfanyl;    or R₄ is phenyl or naphthyl, each of which is unsubstituted or    substituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,    phenyl-C₁-C₃alkyloxy, phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl,    —N(C₁-C₁₂alkyl)₂ or diphenylamino; and    R₅ and R₆ independently of each other are hydrogen, C₁-C₂₀alkyl,    C₂-C₄hydroxyalkyl, C₂-C₁₀alkoxyalkyl, phenyl-C₁-C₃alkyl,    C₁-C₈alkanoyl, C₃-C₁₂alkenoyl or benzoyl;    or R₅ and R₆ are phenyl or naphthyl, each of which is unsubstituted    or substituted by C₁-C₁₂alkyl, benzoyl or C₁-C₁₂alkoxy;    or R₅ and R₆ together are C₂-C₈alkylene which optionally is    interrupted by —O— or —NR₃— and/or optionally is substituted by    C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy.

Interesting are further compounds of formula I, II, III and IV, whereinCh₂ is

Het₁ is furyl, thienyl, pyrrolyl, pyridyl, 2- or 3-benzothienyl or 2- or3-indolyl;each of which is unsubstituted or substituted by C₁-C₁₂alkyl;Het₂ and Het₂′ independently of one another are thienylene, pyrrolylene,benzothienylene, indolylene, indolylenecarbonyl;each of which is unsubstituted or substituted by C₁-C₁₂alkyl;Ar₁ and Ar₁′ independently of one another are phenyl, naphthyl or agroup (B); each of which is unsubstituted or substituted by C₁-C₁₂alkylOR₃, SR₄ or morpholino;Ar₂ is a group (C), (D) or (E); each of which is unsubstituted orsubstituted by C₁-C₁₂alkyl;M is C₁-C₂₀alkylene;X is a direct bond;Y is —O—, —S— or —NR₅—;R₁ is C₁-C₁₂alkyl, phenyl or C₁-C₈alkoxy;R₂ and R₂′ independently of each other are hydrogen, C₁-C₂₀alkyl orphenyl;R₃ is C₁-C₂₀alkyl; andR₄, R₅ and R₆ independently of each other are C₁-C₂₀alkyl or phenyl.

Further preferred are compounds of formula I, whereinCh₁ is

Het₁ is 2-thienyl, 2-furyl, N—(C₁-C₄alkyl)-2-pyrrolyl,N-(phenyl)-2-pyrrolyl, 4-pyridinyl, N—(C₁-C₄alkyl)-3-indolyl orN-(phenyl)-3-indolyl;Het₂ is 2,5-thienylene, 2,5-furylene, N—(C₁-C₄alkyl)-2,5-pyrrolylene,N-(phenyl)-2,5-pyrrolylene, 5-thienylene-2-carbonyl,N—(C₁-C₄alkyl)-indolylene, N—(C₁-C₄alkyl)-indolylenecarbonyl,5-furylene-2-carbonyl or N—(C₁-C₄alkyl)-5-pyrrolylene-2-carbonyl orN-(phenyl)pyrrolylene-2-carbonyl;Ar₁ and Ar₁′ independently of one another are phenyl, naphthyl or agroup (B); each of which is unsubstituted or substituted by 1 to 7 timesby C₁-C₆alkyl, benzoyl, OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino;Ar₂ is phenylene, phenylenecarbonyl, or a group (C), (D), (E) or (F),each of which is unsubstituted or substituted by 1 to 7 times byC₁-C₋alkyl, OR₃, SR₄ or NR₅R₆;X is a direct bond or —CO—;Y is —S— or —NR₅—;R₁ is C₁-C₃alkyl, phenyl or C₁-C₄alkoxy;R₂ is hydrogen, C₁-C₈alkyl or phenyl;R₃ is C₁-C₁₂alkyl;R₄ is C₁-C₁₂alkyl or phenyl; andR₅ and R₆ independently of each other are C₁-C₁₂alkyl or phenyl.

In particular preferred are compounds of the formula I, whereinCh₁ is

Het₁ is thienyl, in particular 2-thienyl;Het₂ is pyrrolylene or indolylene; each of which is substituted byC₁-C₄alkyl;Ar₁′ is phenyl substituted by C₁-C₄alkyl;Ar₂ is a group (C), (D) or (E), in particular (C);X is a direct bond;Y is S or —NR₅—, in particular —NR₅—; andR₁, R₂ and R₅ independently of one another are C₁-C₄alkyl.

Preferred are

in particular

In accordance with the invention, the compounds of the formulae I, II,III and IV can be used as photoinitiators for the photopolymerization ofethylenically unsaturated compounds or of mixtures which comprise suchcompounds.

Another subject of the present invention therefore is aphotopolymerizable composition comprising

(a) at least one ethylenically unsaturated photopolymerizable compoundand

(b) as photoinitiator, at least one compound of the formula I, II, IIIand/or IV

Het₁ is furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,oxazolyl, isoxazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, benzothiadiazolyl,2- or 3-indolyl, indazolyl, quinolyl, isoquinolyl, phthalazinyl,quinoxalinyl, pteridinyl, or bithienyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl;or each of which is substituted by phenyl or by phenyl which isoptionally substituted by one or more OR₃, SR₄ and/or NR₅R₆;or each of which is substituted by C₂-C₁₂alkoxycarbonyl, whichoptionally is interrupted by one or more —O— or —S— and saidC₂-C₁₂alkoxycarbonyl optionally is substituted by one or more hydroxylgroups;or each of which is substituted by one or more OR₃, SR₄, SOR₄, SO₂R₄and/or NR₅R₆, wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form5- or 6-membered rings ma the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the heteroaromatic ring;or each of which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholinoand/or dimethylmorpholino;Het₂ and Het₂′ independently of one another are furylene, thienylene,pyrrolylene, imidazolylene, pyrazolylene, thiazolylene, oxazolylene,isoxazolylene, pyridylene, pyrazinylene, pyridazinylene, triazinylene,benzofurylene, benzothienylene, benzothiazolylene, benzothiadiazolylene,indolylene, indazolylen, quinolylene, isoquinolylene, phthalazinylene,quinoxalinylene, pteridinylene, bithienylene, furylenecarbonyl,thienylenecarbonyl, pyrrolylenecarbonyl, imidazolylenecarbonyl,pyrazolylene, thiazolylenecarbonyl, oxazolylenecarbonyl,pyridylenecarbonyl, pyrazinylenecarbonyl, pyridazinylenecarbonyl,triazinylenecarbonyl, benzofurylenecarbonyl, benzothienylenecarbonyl,benzothiazolylenecarbonyl, benzothiadiazolylenecarbonyl,indolylenecarbonyl, indazolylenecarbonyl, quinolylenecarbonyl,isoquinolylenecarbonyl, phthalazinylenecarbonyl,quinoxalinylenecarbonyl, pteridinylenecarbonyl or bithienylenecarbonyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄, and/orNR₅R₆;or each of which is substituted by phenyl or by naphthyl, said phenyl ornaphthyl optionally is substituted by one or more OR₃, SR₄ and/or NR₅R₆;Ar₁ and Ar₁′ independently of one another are phenyl, naphthyl, benzoyl,naphthoyl, or a group

each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl;or each of which is substituted by phenyl or by phenyl which issubstituted by one or more OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino;or each of which is substituted by C₂-C₁₂alkoxycarbonyl which optionallyis interrupted by one or more —O— or —S— and/or optionally issubstituted by one or more hydroxyl groups;or each of which is substituted by one or more OR₃, SR₄, SOR₄, SO₂R₄NR₅R₆, morpholino and/or dimethylmorpholino;or each of which is substituted by C₁-C₈alkanoyl or benzoyl, saidC₁-C₈alkanoyl or benzoyl optionally is substituted by OR₃, SR₄, SOR₄,SO₂R₄, NR₅R₆, morpholino and/or dimethylmorpholino, wherein thesubstitutents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered ringsvia the radicals R₃, R₄, R₅ and/or R₆ with further substituents on thephenyl ring;provided that(i) if in formula I, Ch₁ is

Ar₁′ is phenyl, Het₂ is 5-phenyl-4,3-isoxazolylene and R₂ is phenyl,then R₁ is not phenyl; and(ii) if, in formula I, Ch₁ is

Het₁ is 2-thienyl and R₂ is phenyl, then R₁ is not phenyl;Ar₂ is phenylene, naphthylene, phenylenecarbonyl, naphthylenecarbonyl,or a group

each of which is unsubstituted or substituted 1 to 6 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆;M Ls C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which is interrupted by one ormore —O— or —S—, saidC₁-C₂₀alkylene and C₂-C₂₀alkylene optionally is substituted by one ormore halogen, OR₃, phenyl or phenyl substituted by OR₃, SR₄ and/orNR₅R₆;or M is phenylene or naphthylene, each of which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/orNR₅R₆;X is a direct bond, —O—, —S—, —NR₅— or —O—;Y is —O—, —S—, —NR₅—, —CO— or —CH₂—;R₁ is hydrogen, C₃-C₈cycloalkyl; or is C₁-C₁₂alkyl which isunsubstituted or substituted by one or more halogen, phenyl and/or CN;or R₁ is C₂-C₅alkenyl; or is phenyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ and/orNR₅R₆;or R₁ is C₁-C₈alkoxy, benzyloxy; or phenoxy which optionally issubstituted by one or more C₁-C₆alkyl and/or halogen;R₂ and R₂′ independently of each other are hydrogen; unsubstitutedC₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or more halogen, OR₃,phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₃-C₉cycloalkyl; or are C₂-C₂₀alkyl interrupted by oneor more —O— or —S—, and/or optionally substituted by one or morehalogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are phenyl which is unsubstituted or substituted by one ormore C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₂-C₂₀alkanoyl or benzoyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, phenyl, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₂-C₁₂alkoxycarbonyl optionally interrupted by one ormore —O— or —S— and/or optionally substituted by one or more hydroxylgroups;or R₂ and R₂′ are phenoxycarbonyl which is unsubstituted or substitutedby C₁-C₆alkyl, halogen, phenyl, OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are CN, —CONR₈R₆, NO₂, C₁-C₄haloalkyl, S(O)_(m)—C₁-C₆alkylor S(O)_(m)-phenyl which is optionally substituted by C₁-C₁₂alkyl orSO₂—C₁-C₆alkyl;or R₂ and R₂′ are SO₂O-phenyl which optionally is substituted byC₁-C₁₂alkyl;or R₂ and R₂′ are furyl, thienyl, pyrrolyl or pyridyl;m is 1 or 2;R₃ is hydrogen, C₁-C₂₀alkyl or phenyl-C₁-C₃alkyl;or R₃ is C₁-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)—(C₁-C₄alkyl), —O(CO)phenyl, —(CO)OH and/or —(CO)O(C₁-C₄alkyl);or R₃ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—;or R₃ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl),C₁-C₈alkanoyl, C₂-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl;or R₃ is benzoyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, halogen, OH and/or C₁-C₄alkoxy;or R₃ is phenyl or naphthyl each of which is unsubstituted orsubstituted by halogen, OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/ordiphenylamino;n is 1-20;R₄ is hydrogen, C₁-C₂₀alkyl, C₂-C₁₂alkenyl, C₃-C₈cycloalkyl orphenyl-C₁-C₃alkyl;or R₄ is C₁-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl);or R₄ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—;or R₄ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl),C₁-C₈alkanoyl, C₂-C₁₂alkenyl or C₃-C₆alkenoyl;or R₄ is benzoyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, halogen, OH, C₁-C₄alkoxy or C₁-C₄alkylsulfanyl;or R₄ is phenyl or naphthyl, each of which is unsubstituted orsubstituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenyl-C₁-C₃alkyloxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂,diphenylamino, —(CO)O(C₁-C₈alkyl), —(CO)—C₁-C₈alkyl or(CO)N(C₁-C₈alkyl)₂; andR₅ and R₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁₀alkoxyalkyl, C₂-C₅alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl, C₁-C₈alkanoyl, C₃-C₁₂-alkenoyl or benzoyl;or R₅ and R₆ are phenyl or naphthyl, each of which is unsubstituted orsubstituted by C₁-C₁₂alkyl, benzoyl or C₁-C₁₂alkoxy;or R₅ and R₆ together are C₂-C₈alkylene which optionally is interruptedby —O—, —S— or —NR₃— and/or optionally substituted by hydroxyl,C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy.

Preferred compounds of the formula I, II, III and IV are as definedabove.

The composition may comprise additionally to the photoinitiator (b) atleast one further photoinitiator (c), and/or other additives (d).

The unsaturated compounds (a) may include one or more olefinic doublebonds. They may be of low (monomeric) or high (oligomeric) molecularmass. Examples of monomers containing a double bond are alkyl,hydroxyalkyl or amino acrylates, or alkyl, hydroxyalkyl or aminomethacrylates, for example methyl, ethyl, butyl, 2-ethylhexyl or2-hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate orethyl methacrylate. Silicone acrylates are also advantageous. Otherexamples are acrylonitrile, acrylamide, methacrylamide, N-substituted(meth)acrylamides, vinyl esters such as vinyl acetate, vinyl ethers suchas isobutyl vinyl ether, styrene, alkyl- and halostyrenes,N-vinylpyrrolidone, vinyl chloride or vinylidene chloride.

Examples of monomers containing two or more double bonds are thediacrylates of ethylene glycol, propylene glycol, neopentyl glycol,hexamethylene glycol or of bisphenol A, and4,4′-bis(2-acryl-oyloxyethoxy)diphenylpropane, trimethylolpropanetriacrylate, pentaerythritol triacrylate or tetraacrylate, vinylacrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallylphosphate, triallyl isocyanurate or tris(2-acryloylethyl)isocyanurate.

Examples of polyunsaturated compounds of relatively high molecular mass(oligomers) are acrylated epoxy resins, polyesters containing acrylate-,vinyl ether- or epoxy-groups, and also polyurethanes and polyethers.Further examples of unsaturated oligomers are unsaturated polyesterresins, which are usually prepared from maleic acid, phthalic add andone or more diols and have molecular weights of from about 500 to 3000.In addition it is also possible to employ vinyl ether monomers andoligomers, and also maleate-terminated oligomers with polyester,polyurethane, polyether, polyvinyl ether and epoxy main chains. Ofparticular suitability are combinations of oligomers which carry vinylether groups and of polymers as described in WO 90/01512. However,copolymers of vinyl ether and maleic acid-functionalized monomers arealso suitable. Unsaturated oligomers of this kind can also be referredto as prepolymers.

Particularly suitable examples are esters of ethylenically unsaturatedcarboxylic acids and polyols or polyepoxides, and polymers havingethylenically unsaturated groups in the chain or in side groups, forexample unsaturated polyesters, polyamides and polyurethanes andcopolymers thereof, polymers and copolymers containing (meth)acrylicgroups in side chains, and also mixtures of one or more such polymers.

Examples of unsaturated carboxylic acids are acrylic acid, methacrylicacid, crotonic add, itaconic acid, cinnamic acid, and unsaturated fattyacids such as linolenic acid or oleic acid. Acrylic and methacrylic acidare preferred.

Suitable polyols are aromatic and, in particular, aliphatic andcycloaliphatic polyols. Examples of aromatic polyols are hydroquinone,4,4′-dihydroxydiphenyl, 2,2-di(4-hydroxyphenyl)propane, and alsonovolaks and resols. Examples of polyepoxides are those based on theabovementoned polyols, especially the aromatic polyols, andepichlorohydrin. Other suitable polyols are polymers and copolymerscontaining hydroxyl groups in the polymer chain or in side groups,examples being polyvinyl alcohol and copolymers thereof orpolyhydroxyalkyl methacrylates or copolymers thereof. Further polyolswhich are suitable are oligoesters having hydroxyl end groups.

Examples of aliphatic and cycloaliphatic polyols are alkylenediolshaving preferably 2 to 12 C atoms, such as ethylene glycol, 1,2- or1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol,octanediol, dodecanediol, diethylene glycol, triethylene glcyol,polyethylene glycols having molecular weights of preferably from 200 to1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-dihydroxymethylcyclohexane, glycerol, tris(β-hydroxyethyl)amine,trimethylolethane, trimethylolpropane, pentaerythritol,dipentaerythritol and sorbitol.

The polyols may be partially or completely esterified with onecarboxylic acid or with different unsaturated carboxylic adds, and inpartial esters the free hydroxyl groups may be modified, for exampleetherified or esterified with other carboxylic acids.

Examples of esters are:

trimethylolpropane triacrylate, trimethylolethane triacrylate,trimethylolpropane trimeth-acrylate, trimethylolethane trimethacrylate,tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate,tetraethylene glycol diacrylate, pentaerythritol diacrylate,pentaerythritol triacrylate, pentaerythritol tetraacrylate,dipentaerythritol diacrylate, dipentaerythritol triacrylate,dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate,dipentaerythritol hexaacrylate, tripentaerythritol octaacrylate,pentaerythritol dimethacrylate, pentaerythritol trimethacrylate,dipentaerythritol dimethacrylate, dipentaerythritol tetramethacrylate,tripen-ta-erythritol octamethacrylate, pentaerythritol diitaconate,dipentaerythritol tris-itaconate, dipentaerythritol pentaitaconate,dipentaerythritol hexaitaconate, ethylene glycol diacrylate,1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanedioldiitaconate, sorbitol triacrylate, sorbitol tetraacrylate,pentaerythritol-modified triacrylate, sorbitol tetra methacrylate,sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates andmethacrylates, glycerol diacrylate and triacrylate, 1,4-cyclohexanediacrylate, bisacrylates and bismethacrylates of polyethylene glycolwith a molecular weight of from 200 to 1500, or mixtures thereof.

Also suitable as components (a) are the amides of identical or differentunsaturated carboxylic acids with aromatic, cycloaliphatic and aliphaticpolyamines having preferably 2 to 6, especially 2 to 4, amino groups.Examples of such polyamines are ethylenediamine, 1,2- or1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine,1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine,dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine,phenylenediamine, bisphenylenediamine, di-β-aminoethyl ether,diethylenetriamine, triethylenetetramine, di(β-aminoethoxy) ordi(β-aminopropoxy)ethane. Other suitable polyamines are polymers andcopolymers, preferably with additional amino groups in the side chain,and oligoamides having amino end groups. Examples of such unsaturatedamides are methylenebisacrylamide, 1,6-hexamethylenebisacrylamide,diethylenetriaminetrismethacrylamide, bis(methacrylamidopropoxy)ethane,β-methacrylamidoethyl methacrylate andN[(β-hydroxyethoxy)ethyl]acrylamide.

Suitable unsaturated polyesters and polyamides are derived, for example,from maleic add and from diols or diamines. Some of the maleic add canbe replaced by other dicarboxylic adds. They can be used together withethylenically unsaturated comonomers, for example styrene. Thepolyesters and polyamides may also be derived from dicarboxylic acidsand from ethylenically unsaturated diols or diamines, especially fromthose with relatively long chains of, for example 6 to 20 C atoms.Examples of polyurethanes are those composed of saturated or unsaturateddiisocyanates and of unsaturated or, respectively, saturated diols.

Polymers with (meth)acrylate groups in the side chain are likewiseknown. They may, for example, be reaction products of epoxy resins basedon novolaks with (meth)acrylic acid, or may be homo- or copolymers ofvinyl alcohol or hydroxyalkyl derivatives thereof which are esterifiedwith (meth)acrylic acid, or may be homo- and copolymers of(meth)acrylates which are esterified with hydroxyalkyl(meth)acrylates.

Other suitable polymers with acrylate or methacrylate groups in the sidechains are, for example, solvent soluble or alkaline soluble polyimideprecursors, for example poly(amic acid ester) compounds, having thephotopolymerizable side groups either attached to the backbone or to theester groups in the molecule, i.e. according to EP 624826. Sucholigomers or polymers can be formulated with the new photoinitiators andoptionally reactive diluents, like polyfunctional (meth)acrylates inorder to prepare highly sensitive polyimide precursor resists.

The photopolymerizable compounds can be used alone or in any desiredmixtures. It is preferred to use mixtures of polyol(meth)acrylates.

Examples of the component (a) are also polymers or oligomers having atleast two ethylenically unsaturated groups and at least one carboxylfunction within the molecule structure, such as a resin obtained by thereaction of a saturated or unsaturated polybasic acid anhydride with aproduct of the reaction of an epoxy compound and an unsaturatedmonocarboxylic acid, for example, photosensitive compounds as describedin JP 6-1638 and JP 10-301276 and commercial products such as EB9696,UCB Chemicals; KAYARAD TCR1025, Nippon Kayaku Co., LTD., or an additionproduct formed between a carboxyl group-containing resin and anunsaturated compound having an α,β-unsaturated double bond and an epoxygroup (for example, ACA200M, Daicel Industries, Ltd.).

Preferred is a photopolymerizable composition comprising as component(a) a compound having at least two ethylenically unsaturated bonds andat least one carboxylic acid group in the molecule.

As diluent, a mono- or multi-functional ethylenically unsaturatedcompound, or mixtures of several of said compounds, can be included inthe above composition up to 70% by weight based on the solid portion ofthe composition.

The unsaturated compounds (a) can also be used as a mixture withnon-photopolymerizable, film-forming components. These may, for example,be physically drying polymers or solutions thereof in organic solvents,for instance nitrocellulose or cellulose acetobutyrate. They may also,however, be chemically and/or thermally curable (heat-curable) resins,examples being polyisocyanates, polyepoxides and melamine resins, aswell as polyimide precursors. The use of heat-curable resins at the sametime is important for use in systems known as hybrid systems, which in afirst stage are photopolymerized and in a second stage are crosslinkedby means of thermal aftertreatment

The invention also provides compositions comprising as component (a) atleast one ethylenically unsaturated photopolymerizable compound which isemulsified or dissolved in water. Many variants of suchradiation-curable aqueous prepolymer dispersions are commerciallyavailable. A prepolymer dispersion is understood as being a dispersionof water and at least one prepolymer dispersed therein. Theconcentration of water in these systems is, for example, from 5 to 80%by weight, in particular from 30 to 60% by weight The concentration ofthe radiation-curable prepolymer or prepolymer mixture is, for example,from 95 to 20% by weight, in particular from 70 to 40% by weight. Inthese compositions the sum of the percentages given for water andprepolymer is in each case 100, with auxiliaries and additives beingadded in varying quantities depending on the intended use.

The radiation-curable, film-forming prepolymers which are dispersed inwater and are often also dissolved are aqueous prepolymer dispersions ofmono- or polyfunctional, ethylenically unsaturated prepolymers which areknown per se, can be initiated by free radicals and have for example acontent of from 0.01 to 1.0 mol of polymerizable double bonds per 100 gof prepolymer and an average molecular weight of, for example, at least400, in particular from 500 to 10,000. Prepolymers with higher molecularweights, however, may also be considered depending on the intendedapplication. Use is made, for example, of polyesters containingpolymerizable C—C double bonds and having an acid number of not morethan 10, of polyethers containing polymerizable C—C double bonds, ofhydroxyl-containing reaction products of a polyepoxide, containing atleast two epoxide groups per molecule, with at least oneα,β-ethylenically unsaturated carboxylic add, ofpolyurethane(meth)acrylates and of acrylic copolymers which containα,β-ethylenically unsaturated acrylic radicals, as are described in EP12339. Mixtures of these prepolymers can likewise be used. Also suitableare the polymerizable prepolymers described in EP 33896, which arethioether adducts of polymerizable prepolymers having an averagemolecular weight of at least 600, a carboxyl group content of from 0.2to 15% and a content of from 0.01 to 0.8 mol of polymerizable C—C doublebonds per 100 g of prepolymer. Other suitable aqueous dispersions, basedon specific alkyl(meth)acrylate polymers, are described in EP 41125, andsuitable water dispersible, radiation-curable prepolymers of urethaneacrylates can be found in DE 2936039.

Further additives which may be included in these radiation-curableaqueous prepolymer dispersions are dispersion auxiliaries, emulsifiers,antioxidants, e.g. 2,2-thiobis(4-methyl-t-butylphenol) or2,6-di-t-butylphenol, light stabilizers, dyes, pigments, fillers, suchas glass or alumina, for example talc, gypsum, silicic add, rutile,carbon black, zinc oxide, iron oxides, reaction accelerators, levellingagents, lubricants, wetting agents, thickeners, flatting agents,antifoams and other auxiliaries customary in paint technology. Suitabledispersion auxiliaries are water-soluble organic compounds which are ofhigh molecular mass and contain polar groups, examples being polyvinylalcohols, polyvinylpyrrolidone or cellulose ethers. Emulsifiers whichcan be used are nonionic emulsifiers and, if desired, ionic emulsifiersas well.

In certain cases it may be of advantage to use mixtures of two or moreof the novel photoinitiators. It is of course also possible to usemixtures with known photoinitiators (c), for example mixtures withcamphor quinone, benzophenone, benzophenone derivatives, acetophenone,acetophenone derivatives, for example α-hydroxycycloalkyl phenyl ketonesor 2-hydroxy-2-methyl-1-phenyl-propanone, dialkoxyacetophenones,α-hydroxy- or α-aminoacetophenones, e.g.(4-methylthiobenzoyl)-1-methyl-1-morpholinoethane,(4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane,4-aroyl-1,3-dioxolanes, benzoin alkyl ethers and benzil ketals, e.g.dimethyl benzil ketal, phenylglyoxalic esters and derivatives thereof,dimeric phenylglyoxalic esters, diacetyl, peresters, e.g. benzophenonetetracarboxylic peresters as described for example in EP 126541,monoacyl phosphine oxides, e.g.(2,4,6-trimethylbenzoyl)diphenylphosphine oxide, bisacylphosphineoxides, bis(2,6-dimethoxy-benzoyl)(2,4,4-trimethyl-pentyl) phosphineoxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,bis(2,4,6-trimethylbenzoyl)-2,4-dipentoxyphenylphosphine oxide,trisacylphosphine oxides, halomethyltriazines, e.g.2-[2-(4-methoxy-phenyl)-vinyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(4-methoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(3,4-dimethoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-methyl-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(4-N,N-di(ethoxycarbonylmethyl)aminophenyl)-4,6-bis(trichloromethyl)-[1,3,5]triazine,2-(4-methoxy-naphthyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-1,3-benzodioxolyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-[4-(pentyloxy)phenyl]ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(3-methyl-2-furanyl)-ethenyl]4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(5-methyl-2-furanyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-2,4-dimethoxy-phenyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(2-methoxy-phenyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-[4-isopropyloxy-phenyl]-ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(3-chloroethoxy-phenyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-bromo-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-chloro-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[3-bromo-4-N,N-di-(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[3-chloro-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,or other halomethyl-triazines as described for example in G. Buhr, R.Dammel and C. Lindley Polym. Mater. Sci. Eng. 61, 269 (1989), and EP0262788; halomethyl-oxazol photoinitiators, such as described in U.S.Pat. No. 4,371,606 and U.S. Pat. No. 4,371,607; 1,2-disulfones, such asdescribed in E. A. Bartmann, Synthesis 5, 490 (1993);hexaarylbisimidazole, and hexaarylbisimidazole/coinitiators systems,e.g. ortho-chlorohexaphenyl-bisimidazole combined with2-mercaptobenzthiazole, bisacridine derivatives, e.g.1,7-bis(9-acridinyl)heptane, ferrocenium compounds, or titanocenes, e.g.bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium.Further, borate salts can be employed as additional photoinitiators.

Where the novel photoinitiator systems are employed in hybrid systems,use is made, in addition to the novel free-radical hardeners, ofcationic photoinitiators, of peroxide compounds, such as benzoylperoxide (other suitable peroxides are described in U.S. Pat. No.4,950,581 column 19, lines 17-25), of aromatic sulfonium-, phosphonium-or iodonium salts as described for example in U.S. Pat. No. 4,950,581,column 18, line 60 to column 19, line 10 orcyclopentadienyl-arene-iron(II) complex salts, for example(η⁶-iso-propylbenzene)(η⁵-cyclopentadienyl)-iron(II)hexafluorophosphate,as well as oxime sulfonic acid esters, as are, for example described inEP 780729. Also pyridinium and (iso)quinolinium salts as described e.g.in EP 497531 and EP 441232 may be used in combination with the newphotoinitiators.

The new photoinitiators, either alone or in mixtures with other knownphotoinitiators and sensitizers, can be used also in the form of adispersion or emulsion in water or aqueous solutions.

Interesting also are compositions comprising besides the compound offormula I, II, III or IV at least one α-aminoketone, in particular(4-methylthiobenzoyl)-1-methyl-1-morpholinoethane.

The photopolymerizable compositions generally comprise 0.05 to 25% byweight, preferably 0.01 to 10% by weight, in particular 0.01 to 5% byweight of the photoinitiator, based on the solid composition. The amountrefers to the sum of all photoinitiators added, if mixtures ofinitiators are employed. Accordingly, the amount either refers to thephotoinitiator (b) or the photoinitiators (b)+(c).

In addition to the photoinitiator the photopolymerizable mixtures mayinclude various additives (d). Examples of these are thermal inhibitors,which are intended to prevent premature polymerization, examples beinghydroquinone, hydroquinone derivatives, p-methoxyphenol, β-naphthol orsterically hindered phenols, such as 2,6-di-tert-butyl-p-cresol in orderto increase the stability on storage in the dark it is possible, forexample, to use copper compounds, such as copper naphthenate, stearateor octoate, phosphorus compounds, for example triphenylphosphine,tributylphosphine, triethyl phosphite, triphenyl phosphite or tribenzylphosphite, quaternary ammonium compounds, for exampletetramethylammonium chloride or trimethylbenzylammonium chloride, orhydroxylamine derivatives, for example N-diethylhydroxylamine. Toexclude atmospheric oxygen during the polymerization it is possible toadd paraffin or similar wax-like substances which, being of inadequatesolubility in the polymer, migrate to the surface in the beginning ofpolymerization and form a transparent surface layer which prevents theingress of air. It is also possible to apply an oxygen-impermeable layeron top of the coating, for example poly(vinylalcohol-co-vinylacetate).Light stabilizers which can be added in a small quantity are UVabsorbers, for example those of the hydroxyphenylbenzotriazole,hydroxyphenyl-benzophenone, oxalamide or hydroxyphenyltriazine type.These compounds can be used individually or in mixtures, with or withoutsterically hindered amines (HALS).

Examples of such UV absorbers and light stabilizers are

1. 2-(2′-hydroxyphenyl)benzotriazoles for example2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2‘-hydroxy-’-methylphenyl)-5-chlorobenzotriazole,2-(3′-sec-butyl-5′-tertbutyl-2′-hydroxyphenyl)benzotrizole,2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)-benzotriazole,mixture of2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethyl-hexyl-oxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole,2-(3′-tertbutyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole,2-3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole,2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole, and2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,2,2′-methylene-bis[4(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol];transesterification product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxy-phenyl]-benzotriazolewith polyethylene glycol 300; [R—CH₂CH₂—COO(CH₂)₃]₂— or whereR=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-yl-phenyl.

2. 2-Hydroxybenzophenones, for example the 4-hydroxy-, 4-methoxy-,4-octoxy-, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-, 4,2′,4′-trihydroxy-and 2′-hydroxy-4,4′-dimethoxy derivative.

3. Esters of substituted or unsubstituted benzoicacids, for example4-tert-butylphenyl salicylate, phenyl salicylate, octylphenylsalicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol,benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butylhydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate,octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, and2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

4. Acrylates, for example isooctyl or ethyl α-cyano-β,βdiphenylacrylate, methyl a carbomethoxycinnamate, butyl or methylα-cyano-M-methyl-p-methoxycinnamate, methylα-carboxymethoxy-p-methoxycinnamate andN-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.

5. Sterically hindered amines, for examplebis-(2,2,6,6-tetramethylpiperidyl) sebacate,bis-(2,2,6,6-tetramethylpiperidyl) succinate,bis-(1,2,2,6,6-pentamethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl)n-butyl-3,5-di-tert-butyl-hydroxybenzylmalonate, condensation product of1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, condensation product ofN,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexa-methylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,tris-(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane tetraoate,1,1′-1,2-ethandiyl)bis(3,3,5,5-tetramethyl-piperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis-(1,2,2,6,6-pentamethylpiperidyl)2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro-[4.5]-decane-2,4-dione,bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate,bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate, condensationproduct ofN,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-morpholino-2,6-dichloro-1,3,5-triazine, condensation product of2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis-(3-aminopropyl-amino)ethane, condensation product of2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis-(3-aminopropylamino)-ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione and3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidine-2,5-dione.

6. Oxalamides for example 4,4′-dioctyloxyoxanilide,2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butyloxanilide,2,2′-didodecyloxy-5,5′di-tert-butyloxanilide,2-ethoxy-2-ethyl-oxanilide, N,N′-bis-(3-dimethylaminopropyl)oxalamide,2-ethoxy-5-tert-butyl-2′-ethyloxanilide and its mixture with2-ethoxy-2′-ethyl-5,4′-di-tert-butyloxanilide, mixtures of o- andp-methoxy- and of o- and p-ethoxy-disubstituted oxanilides.

7. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyloxy-phenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-decyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,6-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[4-dodecyl/tridecyl-oxy-(2-hydroxypropyl)oxy-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

8. Phosphites and phosphonites, for example triphenyl phosphite,diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythrityl diphosphite, tris-(2,4-di-tert-butylphenyl) phosphite,diisodecyl pentaerythrityl diphosphite,bis-(2,4-di-tert-butylphenyl)pentaerythrityl diphosphite,bis-(2,6-di-tert-butyl-4-methylphenyl)pentaerythrityl diphosphite,bis-isodecyloxy pentaerythrityl diphosphite,bis-(2,4-di-tert-butyl-6-methylphenyl)pentaerythrityl diphosphite,bis-(2,4,6-tri-tert-butylphenyl) pentaerythrityl diphosphite, tristearylsorbityl triphosphite,tetrakis-(2,4-di-tert-butylphenyl)-4,4′-biphenylene diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocine,6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine,bis-(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite andbis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite.

To accelerate the photopolymerization it is possible to add amines ascomponent (d), for example triethanolamine, N-methyldiethanolamine,ethyl-p-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate,2-ethylhexyl-p-dimethylaminobenzoate,octyl-para-N,N-dimethylaminobenzoate,N-(2-hydroxyethyl)-N-methyl-para-toluidine or Michler's ketone. Theaction of the amines can be intensified by the addition of aromaticketones of the benzophenone type. Examples of amines which can be usedas oxygen scavengers are substituted N,N-dialkylanilines, as aredescribed in EP 339841. Other accelerators, coinitiators andautoxidizers are thiols, thioethers, disulfides, phosphonium salts,phosphine oxides or phosphines, as described, for example, in EP 438123,in GB 2180358 and in JP Kokai Hei 6-68309.

It is further possible to add chain transfer agents which are customaryin the art to the compositions according to the invention as component(d). Examples are mercaptans, amines and benzothiazol.

Photopolymerization can also be accelerated by adding furtherphotosensitizers or coinitiators (as component (d)) which shift orbroaden the spectral sensitivity. These are, in particular, aromaticcompounds, for example benzophenone and derivatives thereof,thioxanthone and derivatives thereof, anthraquinone and derivativesthereof, coumarin and phenothiazine and derivatives thereof, and also3-(aroylmethylene)thiazolines, rhodanine, camphorquinone, but alsoeosine, rhodamine, erythrosine, xanthene, thioxanthene, acridine, e.g.9-phenylacridine, 1,7-bis(9-acridinyl)heptane,1,5-bis(9-acridinyl)pentane, cyanine and merocyanine dyes.

Specific examples of such compounds are

I. Thioxanthones

Thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone,1-chloro-4-propoxythioxanthone, 2-dodecylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone,1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone,3-(2-methoxyethoxycarbonyl)thioxanthone, 4-butoxycarbonylthioxanthone,3-butoxycarbonyl-7-methylthioxanthone, 1-cyano-3-chlorothioxanthone,1-ethoxycarbonyl-3-chlorothioxanthone,1-ethoxycarbonyl-3-ethoxythioxanthone,1-ethoxycarbonyl-iminothioxanthone,1-ethoxycarbonyl-3-phenylsulfurylthioxanthone,3,4-di-[2-(2-methoxyethoxy)ethoxycarbonyl]-thioxanthone,1,3-dimethyl-2-hydroxy-H-thioxanthen-9-one 2-ethylhexylether,1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone,2-methyl-6-dimethoxymethyl-thioxanthone,2-methyl-6-(1,1-dimethoxybenzyl)thioxanthone,2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone,N-allythioxanthone-3,4-dicarboximide,N-octylthioxanthone-3,4-dicarboximide,N-(1,1,3,3-tetramethylbutyl)-thioxanthone-3,4-dicarboximide,1-phenoxythioxanthone, 6-ethoxycarbonyl-2-methoxythioxanthone,6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone-2-carboxylic acidpolyethyleneglycol ester,2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthon-2-yloxy)-N,N,N-trimethyl-1-propanaminiumchloride;

2. Benzophenones

benzophenone, 4-phenyl benzophenone, 4-methoxy benzophenone,4,4′-dimethoxy benzophenone, 4,4′-dimethyl benzophenone,4,4′-dichlorobenzophenone 4,4′-bis(dimethylamino)-benzophenone,4,4′-bis(diethylamino)benzophenone,4,4′-bis(methylethylamino)benzophenone,4,4′-bis(p-isopropylphenoxy)benzophenone, 4-methyl benzophenone,2,4,6-trimethylbenzophenone, 4-(4-methylthiophenyl)-benzophenone,3,3′-dimethyl-4-methoxy benzophenone, methyl-2-benzoylbenzoate,4-(2-hydroxyethylthio)-benzophenone, 4-(4-tolylthio)-benzophenone,1-[4-(4-benzoyl-phenylsulfanyl)-phenyl]-2-methyl-2-(toluene-4-sulfonyl)-propan-1-one,4-benzoyl-N,N,N-trimethylbenzenemethanaminium chloride,2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethyl-1-propanaminium chloridemonohydrate, 4-(13-acryloyl-1,4,7,10,13-pentaoxatridecyl)-benzophenone,4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyl)oxy]ethyl-benzenemethanaminiumchloride;

3. Coumarins

Coumarin 1, Coumarin 2, Coumarin 6, Coumarin 7, Coumarin 30, Coumarin102, Coumarin 106, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin307, Coumarin 314, Coumarin 314T, Coumarin 334, Coumarin 337, Coumarin500, 3-benzoyl coumarin, 3-benzoyl-7-methoxycoumarin,3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7-dipropoxycoumarin,3-benzoyl-6,8-dichlorocoumarin, 3-benzoyl-6-chloro-coumarin,3,3′-carbonyl-bis[5,7-di(propoxy)-coumarin],3,3′-carbonyl-bis(7-methoxycoumarin),3,3′-carbonyl-bis(7-diethylamino-coumarin), 3-isobutyroylcoumarin,3-benzoyl-5,7-dimethoxy-coumarin, 3-benzoyl-5,7-diethoxy-coumarin,3-benzoyl-5,7-dibutoxycoumarin,3-benzoyl-5,7-di(methoxyethoxy)-coumarin,3-benzoyl-5,7-di(allyloxy)coumarin, 3-benzoyl-7-dimethylaminocoumarin,3-benzoyl-7-diethylaminocoumarin, 3-isobutyroyl-7-dimethylaminocoumarin,5,7-dimethoxy-3-(1-naphthoyl)-coumarin,5,7-diethoxy-3-(1-naphthoyl)-coumarin, 3-benzoylbenzo[f]coumarin,7-diethylamino-3-thienoylcoumarin,3-(4-cyanobenzoyl)-5,7-dimethoxycoumarin,3-(4-cyanobenzoyl)-5,7-dipropoxycoumarin,7-dimethylamino-3-phenylcoumarin, 7-diethylamino-3-phenylcoumarin, thecoumarin derivatives disclosed in JP 09-179299-A and JP 09-325209-A, forexample7-[{4-chloro-6-(diethylamino)-S-triazine-2-yl}amino]-3-phenylcoumarin;

4. 3-(aroylmethylene)thiazolines

3-methyl-2-benzoylmethylene-β-naphthothiazoline,3-methyl-2-benzoylmethylene-benzothiazoline,3-ethyl-2-propionylmethylene-β-naphthothiazoline;

5. Rhodanines

4-dimethylaminobenzalrhodanine, 4-diethylaminobenzalrhodanine,3-ethyl-5-(3-octyl-2-benzothiazolinylidene)-rhodanine, the rhodaninederivatives, formulae [1], [2], [7], disclosed in JP 08-305019A;

6. Other compounds

acetophenone, 3-methoxyacetophenone, 4-phenylacetophenone, benzil,4,4′-bis(dimethylamino)benzil, 2-acetylnaphthalene, 2-naphthaldehyde,dansyl acid derivatives, 9,10-anthraquinone, anthracene, pyrene,aminopyrene, perylene, phenanthrene, phenanthrenequinone, 9-fluorenone,dibenzosuberone, curcumin, xanthone, thiomichler's ketone,α-(4-dimethylaminobenzylidene) ketones, e.g.2,5-bis(4-diethylaminobenzylidene)cyclopentanone,2-(4-dimethylamino-benzylidene)indan-1-one,3-(4-dimethylamino-phenyl)-1-indan-5-yl-propenone,3-phenylthiophthalimide, N-methyl-3,5-di(ethylthio)phthalimide,N-methyl-3,5-di(ethylthio)-phthalimide, phenothiazine,methylphenothiazine, amines, e.g. N-phenylglycine, ethyl4-dimethylaminobenzoate, butoxyethyl 4-dimethylaminobenzoate,4-dimethylaminoacetophenone, triethanolamine, methyldiethanolamine,dimethylaminoethanol, 2-(dimethylamino)ethyl benzoate,poly(propylenegylcol)-4-(dimethylamino)benzoate.

A photopolymerizable composition, comprising as further additive (d) aphotosensitizer compound selected from the group consisting ofbenzophenone and its derivatives, thioxanthone and its derivatives,anthraquinone and its derivatives, or coumarin derivatives is preferred.

The curing process can be assisted by adding photosensitizers, inparticular, in compositions which are pigmented (for example withtitanium dioxide), and also by adding a component which under thermalconditions forms free radicals, for example an azo compound such as2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), a triazene, diazosulfide, pentazadiene or a peroxy compound, for instance a hydroperoxideor peroxycarbonate, for example t-butyl hydroperoxide, as described forexample in EP 245639.

The compositions according to the invention may comprise as furtheradditive (d) a photoreducable dye, e.g., xanthene-, benzoxanthene-,benzothioxanthene, thiazine-, pyronine-, porphyrine- or acridine dyes,and/or trihalogenmethyl compounds which can be cleaved by irradiation.Similar compositions are for example described in EP 445624.

Further additives known in the art may be added as component (d), as forexample flow improvers, adhesion promoters, such asvinyltrimethoxysilane, vinyltriethoxysilanevinyltris(2-methoxyethoxy)silane,N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-amino-ethyl)3aminopropyltrimethoxysilane,3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane,3-glycidoxypropylmethyldimethoxysilane,2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane,3-methacryloxypropyltrimethoxysilane and3-mercaptopropyltrimethoxysilane. Surfactants, optical brighteners,pigments, dyes, wetting agents, levelling assistants, dispersants,aggregation preventers, antioxidants or fillers are further examples foradditives (d).

In order to cure thick and pigmented coatings it is appropriate to addglass microspheres or pulverized glass fibres, as described for examplein U.S. Pat. No. 5,013,768.

The choice of additive(s) (d) is made depending on the field ofapplication and on properties required for this field. The additivesdescribed above are customary in the art and accordingly are added inamounts which are usual in the respective application.

Binders (e) as well can be added to the novel compositions. This isparticularly expedient when the photopolymerizable compounds are liquidor viscous substances. The quantity of binder may, for example, be2-98%, preferably 5-95% and especially 20-90%, by weight relative to theoverall solids content. The choice of binder is made depending on thefield of application and on properties required for this field, such asthe capacity for development in aqueous and organic solvent systems,adhesion to substrates and sensitivity to oxygen.

Examples of suitable binders are polymers having a molecular weight ofabout 2,000 to 2,000,000, preferably 5,000 to 1,000,000. Examples ofalkali developable binders are acrylic polymer having carboxylic acidfunction as a pendant group, such as conventionally known copolymersobtained by copolymerizing an ethylenic unsaturated carboxylic acid suchas (meth)acrylic acid, 2-carboxyethyl(meth)acrylic acid,2-carboxypropyl(meth)acrylic acid itaconic acid, crotonic acid, maleicacid, fumaric acid and ω-carboxypolycaprolactone mono(meth)acrylate,with one or more monomers selected from esters of (meth)acrylic add,such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate,butyl(meth)acrylate, benzyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,hydroxyethyl(meth)acrylate, hydroxypropyl (meth)acrylate, glycerolmono(meth)acrylate, tricyclo[5.2.1.0^(2,6)]decan-8-yl (meth)acrylate,glycidyl(meth)acrylate, 2-methylglycidyl(meth)acrylate, 3,4-epoxybutyl(meth)acrylate, 6,7-epoxyheptyl(meth)acrylate,N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate,N,N-dimethylaminopropyl (meth)acrylate; vinyl aromatic compounds, suchas styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, vinylbenzylglycidyl ether, 4-vinylpyridine; amide type unsaturated compounds,(meth)acrylamide diacetone acrylamide, N-methylolacrylamide,N-butoxymethacrylamide N,N-dimethylacrylamide,N,N-dimethylaminopropyl(meth)acrylamide; and polyolefin type compounds,such as butadiene, isoprene, chloroprene and the like;methacrylonitrile, methyl isopropenyl ketone,mono-2-[(meth)acryloyloxy]ethyl succinate, N-phenylmaleimide, maleicanhydride, vinyl acetate, vinyl propionate, vinyl pivalate,vinylpyrrolidone, N,N-dimethylaminoethyl vinyl ether, diallylamine,polystyrene macromonomer, or polymethyl (meth)acrylate macromonomer.Examples of copolymers are copolymers of acrylates and methacrylateswith acrylic acid or methacrylic acid and with styrene or substitutedstyrene, phenolic resins, for example novolak, (poly)hydroxystyrene, andcopolymers of hydroxystyrene with alkyl acrylates, acrylic acid and/ormethacrylic acid. Preferable examples of copolymers are copolymers ofmethyl methacrylate/methacrylic acid, copolymers of benzylmethacrylate/methacrylic acid, copolymers of methyl methacrylate/ethylacrylate/methacrylic acid, copolymers of benzyl methacrylate/methacrylicacid/styrene, copolymers of benzyl methacrylate/methacrylicacid/hydroxyethyl methacrylate, copolymers of methyl methacrylate/butylmethacrylate/methacrylic add/styrene, copolymers of methylmethacrylate/benzyl methacrylate/methacrylic acid/hydroxyphenylmethacrylate. Examples of solvent developable binder polymers arepoly(alkyl methacrylates), poly(alkyl acrylates),poly(benzylmethacrylate-co-hydroxyethylmethacrylate-co-methacrylic add),poly(benzylmethacrylate-co-methacrylic acid); cellulose esters andcellulose ethers, such as cellulose acetate, cellulose acetobutyrate,methylcellulose, ethylcellulose; polyvinylbutyral, polyvinylformal,cyclized rubber, polyethers such as polyethylene oxide, polypropyleneoxide and polytetrahydrofuran; polystyrene, polycarbonate, polyurethane,chlorinated polyolefins, polyvinyl chloride, vinyl chloride/vinylidenecopolymers, copolymers of vinylidene chloride with acrylonitrile, methylmethacrylate and vinyl acetate, polyvinyl acetate, copoly(ethylene/vinylacetate), polymers such as polycaprolactam and poly(hexamethyleneadipamide), and polyesters such as poly(ethylene glycol terephtalate)and poly(hexamethylene glycol succinate) and polyimide binder resins.

The polyimide binder resin in the present invention can either be asolvent soluble polyimide or a polyimide precursor, for example, apoly(amic acid).

Preferred is a photopolymerizable composition, comprising as binderpolymer (e), a copolymer of methacrylate and methacrylic acid.

Interesting further are polymeric binder components as described e.g. inJP 10-171119-A, in particular for use in color filters.

The photopolymerizable compositions can be used for various purposes,for example as printing ink, e.g. screen printing inks, inks for offset-or flexo printing, as a clear finish, as a white or colored finish, forexample for wood or metal, as powder coating, as a coating material,inter alia for paper, wood, metal or plastic, as a daylight-curablecoating for the marking of buildings and roadmarking, for photographicreproduction techniques, for holographic recording materials, for imagerecording techniques or to produce printing plates which can bedeveloped with organic solvents or with aqueous alkalis, for producingmasks for screen printing, as dental filling compositions, as adhesives,as pressure-sensitive adhesives, as laminating resins, as etch resists,solder resists, electroplating resists, or permanent resists, bothliquid and dry films, as photostructurable dielectric, for printedcircuit boards and electronic circuits, as resists to manufacture colorfilters for a variety of display applications or to generate structuresin the manufacturing process of plasma-display panels andelectroluminescence displays, (as for example described in U.S. Pat. No.5,853,446, EP 863534, JP 09-244230-A, JP 10-62980-A, JP 08-171863-A,U.S. Pat. No. 5,840,465, EP 855731, JP 05-271576-A, JP 05-67405-A) forthe production of optical switches, optical lattices (interferencelattice), light circuits, for producing three-dimensional articles bymass curing (W curing in transparent moulds) or by the stereolithographytechnique, as is described, for example, in U.S. Pat. No. 4,575,330, toproduce composite materials (for example styrenic polyesters, which may,if desired, contain glass fibres and/or other fibres and otherauxiliaries) and other thick-layered compositions, for coating orsealing electronic components and integrated circuits, or as coatingsfor optical fibres, or for producing optical lenses, e.g. contact lensesor Fresnel lenses. The compositions according to the invention arefurther suitable for the production of medical equipment, auxiliaries orimplants. Further, the compositions according to the invention aresuitable for the preparation of gels with thermotropic properties, asfor example described in DE 19700064 and EP 678534.

The photoinitiators of the present invention are also suitable for thecomposition of the holographic data storage system. The holographic datastorage system is preferably comprised of a matrix network oflow-refractive index matrix precursors and high-refractive indexphotopolymerizable monomers. The media matrix is formed by in-situpolymerization which yields as cross-linked network in the presence ofthe photopolymerizable monomers which remain “dissolved” and unreacted.The matrix containing unreacted, photopolymerizable monomers can also beformed by other means, for example by using a solid-resin matrixmaterial in which the photoreactive, liquid monomer is homogeneouslydistributed. Then, monochromatic exposure generates the holographicpattern, which according to the light intensity distribution,polymerizes the photoreactive monomers in the solid pre-formed matrix.The unreacted monomers (where light intensity was at a minimum) diffusethrough the matrix, producing a modulation of the refractive index thatis determined by the difference between the refractive indices of themonomer and the matrix and by the relative volume fraction of themonomer. The thickness of the recording layer is in the range of severalmicrometers up to a thickness of one millimeter. Because of such thickholographic data storage layers it is required that the photoinitiatorcombines high photoreactivity with low absorbance, in order to renderthe layer transparent at the laser wavelength to assure that the extentof photopolymerization is as little as possible dependent on theexposure depth into the recording layer.

The novel photoinitiators may additionally be employed as initiators foremulsion polymerizations, pearl polymerizations or suspensionpolymerizations, as polymerization initiators for fixing ordered statesof liquid-crystalline monomers and oligomers, or as initiators forfixing dyes on organic materials.

In coating materials, use is frequently made of mixtures of a prepolymerwith polyunsaturated monomers, which may additionally include amonounsaturated monomer as well. It is the prepolymer here whichprimarily dictates the properties of the coating film, and by varying itthe skilled worker is able to influence the properties of the curedfilm. The polyunsaturated monomer functions as a crosslinking agentwhich renders the film insoluble. The monounsaturated monomer functionsas a reactive diluent, which is used to reduce the viscosity without theneed to employ a solvent.

Unsaturated polyester resins are usually used in two-component systemstogether with a monounsaturated monomer, preferably with styrene. Forphotoresists, specific one-component systems are often used, for examplepolymaleimides, polychalcones or polyimides, as described in DE 2308830.

The novel photoinitiators and mixtures thereof can also be used for thepolymerization of radiation-curable powder coatings. The powder coatingscan be based on solid resins and monomers containing reactive doublebonds, for example maleates, vinyl ethers, acrylates, acrylamides andmixtures thereof. A free-radically UV-curable powder coating can beformulated by mixing unsaturated polyester resins with solid acrylamides(for example methyl methylacrylamidoglycolate) and a novel free-radicalphotoinitiator, such formulations being as described, for example, inthe paper “Radiation Curing of Powder Coating”, Conference Proceedings,Radtech Europe 1993 by M. Wittig and Th. Gohmann. The powder coatingscan also contain binders, as are described, for example, in DE 4228514and in EP 636669. Free-radically UV-curable powder coatings can also beformulated by mixing unsaturated polyester resins with solid acrylates,methacrylates or vinyl ethers and with a novel photoinitiator (orphotoinitiator mixture). The powder coatings may also comprise bindersas are described, for example, in DE 4228514 and in EP 636669. TheUV-curable powder coatings may additionally comprise white or colouredpigments. For example, preferably rutiletitanium dioxide can be employedin concentrations of up to 50% by weight in order to give a cured powdercoating of good hiding power. The procedure normally compriseselectrostatic or tribostatic spraying of the powder onto the substrate,for example metal or wood, melting of the powder by heating, and, aftera smooth film has formed, radiation-curing of the coating withultraviolet and/or visible light, using for example medium-pressuremercury lamps, metal halide lamps or xenon lamps. A particular advantageof the radiation-curable powder coatings over their heat-curablecounterparts is that the flow time after meting the powder particles canbe delayed in order to ensure the formation of a smooth, high-glosscoating. In contrast to heat-curable systems, radiation-curable powdercoatings can be formulated to melt at lower temperatures without theunwanted effect of shortening their lifetime. For this reason, they arealso suitable as coatings for heat-sensitive substrates, for examplewood or plastics. In addition to the novel photoinitiator systems, thepowder coating formulations may also include UV absorbers. Appropriateexamples are listed above in sections 1-8.

The compositions comprising the novel photoinitiators can, for example,also be used as repair materials and as putty materials.

The novel photocurable compositions are suitable, for example, ascoating materials for substrates of all kinds, for example wood,textiles, paper, ceramics, glass, plastics such as polyesters,polyethylene terephthalate, polyolefins or cellulose acetate, especiallyin the form of films, and also metals such as Al, Cu, Ni, Fe, Zn, Mg orCo and GaAs, Si or SiO₂ to which it is intended to apply a protectivelayer or, by means of imagewise exposure, to generate an image.

The novel radiation-sensitive compositions further find application asnegative resists, having a very high sensitivity to light and being ableto be developed in an aqueous alkaline medium without swelling. They aresuitable for the production of printing forms for relief printing,planographic printing, photogravure or of screen printing forms, for theproduction of relief copies, for example for the production of texts inbraille, for the production of stamps, for use in chemical milling or asa microresist in the production of integrated circuits. The compositionsfurther may be used as photopatternable dielectric layer or coating,encapsulating material and isolating coating in the production ofcomputer chips, printed boards and other electric or electroniccomponents. The possible layer supports, and the processing conditionsof the coating substrates, are just as varied.

The novel composition also relates to a photosensitive thermosettingresin composition and a method of forming a solder resist pattern by theuse thereof, and more particularly relates to a novel photosensitivethermosetting resin composition useful as materials for the productionof printed circuit boards, the precision fabrication of metallicarticles, the etching of glass and stone articles, the relief of plasticarticles, and the preparation of printing plates and particularly usefulas a solder resist for printed circuit boards and to a method of forminga solder resist pattern by the steps of exposing a layer of the resincomposition selectively to an actinic ray through a photomask having apattern and developing the unexposed part of the layer.

The solder resist is a substance which is used during the soldering of agiven part to a printed circuit board for the purpose of preventingmolten solder from adhering to irrelevant portions and protectingcircuits. It is, therefore, required to possess such properties as highadhesion, insulation resistance, resistance to soldering temperature,resistance to solvents, resistance to alkalis, resistance to acids, andresistance to plating.

Because the photocurable compositions according to the invention have agood thermal stability and are sufficiently resistant to inhibition byoxygen, they are particularly suitable for the production of colorfilters or color mosaic systems, such as described, for example, in EP320 264. Color filters usually are employed in the manufacturing ofLCD's, projection systems and image sensors. The color filters can beused, for example, for display and image scanner in televisionreceivers, video monitors or computers, in flat panel display technologyetc.

The color filters usually are prepared by forming red, green and bluepixels and a black matrix on a glass substrate. In these processesphotocurable compositions according to the invention can be employed. Aparticularly preferred method of use comprises adding of the coloringmatters, dyes and pigments of red, green and blue colors to thelight-sensitive resin composition of the present invention, coating ofthe substrate with the composition, drying of the coating with a shortheat treatment, patternwise exposure of the coating to actinic radiationand subsequent development of the pattern in an aqueous alkalinedeveloper solution and optionally a heat treatment. Thus, bysubsequently applying a red, green and blue pigmented coating, in anydesired order, on top of each other with this process a color filterlayer with red, green and blue color pixels can be produced.

The development is carried out by washing out the areas which were notpolymerized with a suitable alkali developing solution. This process isrepeated to form the image having plural colors.

In the light-sensitive resin composition of the present invention, witha process in which at least one or more picture elements are formed on atransparent substrate and then an exposure is given from a side of thetransparent substrate, on which the above picture elements are notformed, the above picture elements can be utilized as a light-shieldingmask. In this case, for example, in the case where an overall exposureis given, a position adjustment of a mask gets unnecessary and a concernon a position slippage thereof is removed. And, it is possible to cureall of the part on which the above picture elements are not formed.Further, in this case, it is possible as well to develop and remove apart of the portion on which the above picture elements are not formedby using partially a light-shielding mask.

Since in either case, no gap is formed between the picture elementswhich are formed formerly and those which are formed later, thecomposition of the present invention is suitable for, for example, aforming material for a color filter. To be concrete, the coloringmatters, dyes and pigments of red, green and blue colors are added tothe light-sensitive resin composition of the present invention, and theprocesses for forming an image are repeated to form the picture elementsof red, green and blue colors. Then, the light-sensitive resincomposition to which, for example, the black coloring materials, dyesand pigments are added is provided on an overall face. An overallexposure (or a partial exposure via a light-shielding mask) can beprovided thereon to form the picture elements of a black color all overthe spaces (or all but a partial region of the light-shielding mask)between the picture elements of red, green and blue colors.

In addition to a process in which the light-sensitive resin compositionis coated on a substrate and dried, the light-sensitive resincomposition of the present invention can be used as well for a layertransfer material. That is, the light-sensitive resin composition islayer-wise provided directly on a temporary support, preferably on apolyethylene terephthalate film, or on a polyethylene terephthalate filmon which an oxygen-shielding layer and a peeling layer or the peelinglayer and the oxygen-shielding layer are provided. Usually, a removablecover sheet made of a synthetic resin is laminated thereon for aprotection in handling. Further, there can be applied as well a layerstructure in which an alkali soluble thermoplastic resin layer and anintermediate layer are provided on a temporary support and further alight-sensitive resin composition layer is provided thereon (JP5-173320-A).

The above cover sheet is removed in use and the light-sensitive resincomposition layer is laminated on a permanent support. Subsequently,peeling is carried out between those layer and a temporary support whenan oxygen-shielding layer and a peeling layer are provided, between thepeeling layer and the oxygen-shielding layer when the peeling layer andthe oxygen-shielding layer are provided, and between the temporarysupport and the light-sensitive resin composition layer when either thepeeling layer or the oxygen-shielding layer is not provided, and thetemporary support is removed.

A metal support, glass, ceramics, and a synthetic resin film can be usedas a support for a color filter. Glass and a synthetic resin film whichis transparent and have an excellent dimension stability is particularlypreferred.

The thickness of the light-sensitive resin composition layer is usually0.1 to 50 micrometers, in particular 0.5 to 5 micrometers.

A diluted aqueous solution of an alkaline substance can be used as adeveloping solution for the light-sensitive resin composition of thepresent invention if the composition contains alkali soluble resin oralkali soluble monomers or oligomers, and further a developer solutionprepared by adding a small amount of a water-miscible organic solventthereto is included as well.

Examples of suitable alkaline materials include alkali metal hydroxides(for example, sodium hydroxide and potassium hydroxide), alkali metalcarbonates (for example, sodium carbonate and potassium carbonate),alkali metal bicarbonates (for example, sodium bicarbonate and potassiumbicarbonate), alkali metal silicates (for example, sodium silicate andpotassium silicate), alkali metal metasilicates (for example, sodiummetasilicate and potassium metasilicate), triethanolamine,diethanolamine, monoethanolamine, morpholine, tetraalkylammoniumhydroxides (for example, tetramethylammonium hydroxide), or trisodiumphosphate. The concetration of the alkaline substance is 0.01 to 30weight %, and pH is preferably 8 to 14.

Suitable organic solvents which are miscible with water includemethanol, ethanol, 2-propanol, 1-propanol, butanol, diacetone alcohol,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-butyl ether, diethyleneglycol dimethyl ether,propyleneglycol monomethyl ether acetate, ethyl-3-ethoxypropionate,methyl-3-methoxypropionate, n-butyl acetate, benzyl alcohol, acetone,methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone,2-pentanone, epsilon-caprolactone, gamma-butylolactone,dimethylformamide, dimethylacetoamide, hexamethylphosphoramide, ethyllactate, methyl lactate, epsilon-caprolactam, andN-methyl-pyrrolidinone. The concentration of the organic solvent whichis miscible with water is 0.1 to 30 weight %.

Further, a publicly known surface active agent can be added. Theconcentration of the surface active agent is preferably 0.001 to 10weight %.

The light sensitive resin composition of the present invention can alsobe developed with organic solvents, including blends of two or moresolvents, not containing alkaline compounds. Suitable solvents includemethanol, ethanol, 2-propanol, 1-propanol, butanol, diacetone alcohol,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-butyl ether, diethyleneglycol dimethyl ether,propyleneglycol monomethyl ether acetate, ethyl-3-ethoxypropionate,methyl-3-methoxypropionate, n-butyl acetate, benzyl alcohol, acetone,methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone,2-pentanone, epsilon-caprolactone, gamma-butylolactone,dimethylformamide, dimethylacetamide, hexamethylphosphoramide, ethyllactate, methyl lactate, epsilon-caprolactam, and N-methylpyrrolidinone.Optionally, water can be added to these solvents up to a level at whichstill a clear solution is obtained and at which sufficient solubility ofthe unexposed areas of the light sensitive composition is maintained.

The developer solution can be used in all forms known to the personskilled in the art, for example in form of a bath solution, puddle, or aspraying solution. In order to remove the noncured portion of thelight-sensitive resin composition layer, there can be combined themethods such as rubbing with a rotary brush and rubbing with a wetsponge. Usually, the temperature of the developing solution ispreferably at and around room temperature to 40° C.

The developing time is changeable according to the specific kind of thelight-sensitive resin composition, the alkalinity and temperature of thedeveloping solution, and the kind and concentration of the organicsolvent in the case where it is added. Usually, it is 10 seconds to 2minutes. It is possible to put a rinsing step after the developmentprocessing.

A final heat treatment is preferably carried out after the developmentprocessing. Accordingly, a support having a layer which isphotopolymerized by exposing (hereinafter referred to as a photocuredlayer) is heated in an electric furnace and a drier, or the photocuredlayer is irradiated with an infrared lamp or heated on a hot plate. Theheating temperature and time depend on the composition used and thethickness of the formed layer. In general, heating is preferably appliedat about 120° C. to about 250° C., for about 5 to about 60 minutes.

The pigment which can be comprised in the composition according to thepresent invention, including a pigmented color filter resistcomposition, is preferably a processed pigment, for example a powdery orpasty product prepared by finely dispersing a pigment into at least oneresin selected from the group consisting of acrylic resin, vinylchloride-vinyl acetate copolymer, maleic acid resin and ethyl celluloseresin.

The red pigment comprises, for example, an anthraquinone type pigmentalone, a diketopyrolopyrole type pigment alone, a mixture of them or amixture consisting of at least one of them and a disazo type yellowpigment or an isoindoline type yellow pigment, in particular C. I.Pigment Red 177 alone, C. I. Pigment Red 254 alone, a mixture of C. I.Pigment Red 177 and C. I. Pigment Red 254 or a mixture consisting of atleast one member of C. I. Pigment Red 177 and C. I. Pigment Red 254, andC. I. Pigment Yellow 83 or C. I. Pigment Yellow 139 (“C. I.” refers tothe Color Index, known to the person skilled in the art and publiclyavailable). Further suitable examples for the pigment are C.I. PigmentRed 9, 97, 105, 122, 123, 144, 149, 168, 176, 179, 180, 185, 202, 207,209, 214, 222, 242, 244, 255, 264, 272 and C.I. Pigment Yellow 12, 13,14, 17, 20, 24, 31, 53, 55, 93, 95, 109, 110, 128, 129, 138, 139, 150,153, 154, 155, 166, 168, 185, 199, 213 and C.I. Pigment Orange 43.

Examples of the dyes for red color are C. I. Solvent Red 25, 27, 30, 35,49, 83, 89, 100, 122, 138, 149, 150, 160, 179, 218, 230, C. I. DirectRed 20, 37, 39, 44, and C. I. Add Red 6, 8, 9, 13, 14, 18, 26, 27, 51,52, 87, 88, 89, 92, 94, 97, 111, 114, 115, 134, 145, 151, 154, 180, 183,184, 186, 198, C. I. Basic Red 12, 13, C. I. Disperse Red 5, 7, 13, 17and 58. The Red dyes can be used in combination with yellow and/ororange dyes.

The green pigment comprises for instance a halogenated phthalocyaninetype pigment alone or its mixture with a disazo type yellow pigment, anquinophthalone type yellow pigment or a metal complex, in particular C.I. Pigment Green 7 alone, C. I. Pigment Green 36 alone, or a mixtureconsisting of at least one member of C. I. Pigment Green 7, C. I.Pigment Green 36 and C. I. Pigment Yellow 83, C. I. Pigment Yellow 138or C. I. Pigment Yellow 150. Other suitable green pigments are C.I.Pigment Green 15, 25 and 37.

Examples for suitable green dyes are C. I. Acid Green 3, 9, 16, C. I.Basic Green 1 and 4.

Examples for suitable blue pigments are phthalocyanine type pigments,used either alone or in combination with an dioxazine type violetpigment, for instance, C. I. Pigment Blue 15:6 alone, a combination ofC. I. Pigment Blue 15:6 and C. I. Pigment Violet 23. Further examplesfor blue pigments are such of C. I. Pigment Blue 15:3, 15:4, 16, 22, 28and 60. Other suitable pigments are C. I. Pigment Violet 14, 19, 23, 29,32, 37, 177 and C. I. Orange 73. Examples for suitable blue dyes are C.I. Solvent Blue 25, 49, 68, 78, 94, C. I. Direct Blue 25, 86, 90, 108,C. I. Acid Blue 1, 7, 9, 15, 103, 104, 158, 161, C. I. Basic Blue 1, 3,9, 25, and C. I. Disperse Blue 198.

The pigment of the photopolymeric composition for black matrixpreferably comprises at least one member selected from the groupconsisting of carbon black, titanium black and iron oxide. However, amixture of other pigments which, in total, give the black appearance,can also be used. For example, also C. I. Pigment Black 1, 7 and 31 canbe used alone or in combination.

Other examples of the dyes used for color filter are C. I. SolventYellow 2, 5, 14, 15, 16, 19, 21, 33, 56, 62, 77, 83, 93, 162, 104, 105,114, 129, 130, 162, C. I. Disperse Yellow 3, 4, 7, 31, 54, 61, 201, C.I. Direct Yellow 1, 11, 12, 28, C. I. Acid Yellow 1, 3, 11, 17, 23, 38,40, 42, 76, 98, C. I. Basic Yellow 1, C. I. Solvent Violet 13, 33, 45,46, C. I. Disperse Violet 22, 24, 26, 28, C. I. Acid Violet 49, C. I.Basic Violet 2, 7, 10, C. I. Solvent Orange 1, 2, 5, 6, 37, 45, 62, 99,C. I. Acid Orange 1, 7, 8, 10, 20, 24, 28, 33, 56, 74, C. I. DirectOrange 1, C. I. Disperse Orange 5, C. I. Direct Brown 6, 58, 95, 101,173, C. I. Acid Brown 14, C. I. Solvent Black 3, 5, 7, 27, 28, 29, 35,45 and 46.

In some special cases of manufacturing color filters, complementarycolors, yellow, magenta, cyan and optionally green, are used instead ofred, green and blue. As yellow for this type of color filters, theabovementioned yellow pigments and dyes can be employed. Examples of thecolorants suitable for magenta color are C. I. Pigment Red 122, 144,146, 169, 177, C. I. Pigment Violet 19 and 23. Examples of cyan colorare aluminum phthalocyanine pigments, titanium phthalocyanine pigments,cobalt phthalocyanine pigments, and tin phthalocyanine pigments.

For any color, combinations of more than two pigments can also be used.Especially suitable in color filter applications are powdery processedpigments prepared by finely dispersing the above mentioned pigments intoa resin.

The concentration of the pigment in the total solid component (pigmentsof various colors and resin) is for example in the range of 5% to 80% byweight, in particular in the range of 20% to 45% by weight.

The pigments in the color filter resist composition have preferably amean particle diameter smaller than the wavelength of visible light (400nm to 700 nm). Particularly preferred is a mean pigment diameter of <100nm.

If necessary, the pigments may be stabilized in the photosensitivecomposition by pretreatment of the pigments with a dispersant to improvethe dispersion stability of the pigment in the liquid formulation.

Preferably, the color filter resist composition according to the presentinvention contains additionally at least one addition polymerizablemonomeric compound as component (a).

The ethylenically unsaturated compounds (a) include one or more olefinicdouble bonds. They may be of low (monomeric) or high (oligomeric)molecular mass. Examples of compounds containing a double bond are(meth)acrylic add, alkyl, hydroxyalkyl or aminoalkyl (meth)acrylates,for example methyl, ethyl, n-butyl, isobutyl, tert-butyl, n-propyl,isopropyl, n-hexyl, cyclohexyl, 2-ethylhexyl, isobornyl, benzyl,2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, ethoxyethyl, glycerol,phenoxyethyl, methoxydiethylene glycol, ethoxydiethylene glycol,polyethylene glycol, polypropylene glycol, glycidyl,N,N-dimethylaminoethyl, and N, N-diethylaminoethyl(meth)acrylates. Otherexamples are (meth)acrylonitrile, (meth)acrylamide, N-substituted(meth)acrylamides such as N,N-dimethyl(meth)acrylamide,N,N-diethyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide,N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide,N-butyl(meth)acrylamide, and N-(meth)acryloylmorpholine, vinyl esterssuch as vinyl acetate, vinyl ethers such as isobutyl vinyl ether,styrene, alkyl-, hydroxy- and halostyrenes, N-vinylpyrrolidone,N-vinylcaprolactam, N-vinylacetoamide, N-vinylformamide, vinyl chlorideand vinylidene chloride.

Examples of polyunsaturated compounds of relatively high molecular mass(oligomers) are polyesters, polyurethanes, polyethers and polyamides,which contain ethylenically unsaturated carboxylates.

Particularly suitable examples are esters of an ethylenicallyunsaturated carboxylic acid with a polyol or polyepoxide.

Examples of unsaturated carboxylic acids are acrylic acid, methacrylicacid, crotonic acid, itaconic acid, cinnamic acid, and unsaturated fattyacids such as linolenic acid or oleic acid. Acrylic and methacrylicacids are preferred.

Suitable polyols are aromatic, in particular, aliphatic andcycloaliphatic polyols. Examples of aromatic polyols are hydroquinone,4,4′-dihydroxydiphenyl, 2,2-bis(4-hydroxyphenyl) methane,2,2-bis(4-hydroxyphenyl)propane,2,2-bis(4-hydroxyphenyl)hexafluoropropane,9,9-bis(4-hydroxyphenyl)fluorene, novolacs and resols. Examples ofaliphatic and cycloaliphatic polyols are alkylenediols having preferably2 to 12 C atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-,1,3- or 1,4-butanediol, pentanediol, hexanediol, octanediol,dodecanediol, diethylene glycol, triethylene glcyol, polyethyleneglycols having molecular weights of preferably from 200 to 1500,1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-dihydroxymethylcyclohexane, glycerol, triethanolamine,trimethylolethane, trimethylolpropane, pentaerythritol, pentaerythritolmonooxalate, dipentaerythritol, ethers of pentaerythritol with ethyleneglycol or propylene glycol, ethers of dipentaerythritol with ethyleneglycol or propylene glycol, sorbitol,2,2-bis[4-(2-hydroxyethoxy)phenyl]methane,2,2-bis[4-(2-hydroxyethoxy)phenylpropane and9,9-bis[4-(2-hydroxyethoxy)phenylfluorene. Other suitable polyols arepolymers and copolymers containing hydroxyl groups in the polymer chainor in side groups, examples being homopolymers or copolymers comprisingvinyl alcohol or comprising hydroxyalkyl(meth)acrylates. Further polyolswhich are suitable are esters and urethanes having hydroxyl end groups.

The polyols may be partially or completely esterified with oneunsaturated carboxylic add or with different unsaturated carboxylicacids, and in partial esters the free hydroxyl groups may be modified,for example etherified or esterified with other carboxylic acids.

Examples of esters based on polyols are trimethylolpropanetri(meth)acrylate, trimethylolpropane tri(acryloyloxypropyl)ether,trimethylolethane tri(meth)acrylate, ethylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,tetraethylene glycol di(meth)acrylate, tetramethylene glycoldi(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritoldi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, pentaerythritol tri(meth)acrylate monooxalate,dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate,dipentaerythritol tetra(meth)acrylate, dipentaerythritolpenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate mono(2-hydroxyethyl)ether,tripentaerythritol octa(meth)acrylate, 1,3-butanediol di(meth)acrylate,1,4-butanediol diitaconate, hexanediol di(meth)acrylate,1,4-cyclohexanediol di(meth)acrylate, sorbitol tri(meth)acrylate,sorbitol tetra(meth)acrylate, sorbitol penta(meth)acrylate, sorbitolhexa(meth)acrylate, oligoester(meth)acrylates, glycerol di(meth)acrylateand tri(meth)acrylate, di(meth)acrylates of polyethylene glycol with amolecular weight of from 200 to 1500, pentaerythritol diitaconate,dipentaerythritol trisitaconate, dipentaerythritol pentaitaconate,dipentaerythritol hexaitaconate, ethylene glycol diitaconate, propyleneglycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanedioldiitaconate, tetramethylene glycol diitaconate, sorbitol tetraitaconate,ethylene glycol dicrotonate, tetramethylene glycol dicrotonate,pentaerythritol dicrotonate, ethylene glycol dimaleate, tiethyleneglycol dimaleate, pentaerythritol dimaleate, sorbitol tetramaleate, ormixtures thereof.

Other examples are pentaerythritol and dipentaerythritol derivativesshown in the following formula (XII) and (XIII).

whereinM₁ is —(CH₂CH₂O)— or —]CH₂CH(CH₃)O]—,R₁₀ is —COCH═CH₂ or —COC(CH₃)═CH₂,p is 0 to 6 (total of p: 3-24), and q is 0 to 6 (total of q: 2-16).

Examples of polyepoxides are those based on the abovementioned polyolsand epichlorohydrin. Typical examples arebis(4-glycidyloxyphenyl)methane, 2,2-bis(4-glycidyloxyphenyl)propane,2,2-bis(4-glycidyloxyphenyl)hexafluoropropane,9,9-bis(4-glycidyloxyphenyl)fluorene,bis[4-(2-glycidyloxyethoxy)phenyl]methane,2,2-bis[4-(2-glycidyloxyethoxy)phenyl]propane,2,2-bis[4-(2-glycidyloxyethoxy)phenyl]hexafluoropropane,9,9-bis[4-(2-glycidyloxyethoxy)phenyl]fluorene,bis[4-(2-glycidyloxypropoxy)phenyl]methane,2,2-bis[4-(2-glycidyloxypropoxy)phenyl]propane,2,2-bis[4-(2-glycidyloxypropoxy)phenyl]hexafluoropropane,9,9-bis[4-(2-glycidyloxypropoxy)phenyl]fluorene, and glycidyl ethers ofphenol and cresol novolacs.

Typical examples of component (a) based on polyepoxides are2,2-bis[4-{(2-hydroxy-3-acryloxy)propoxy}phenyl]propane,2,2-bis[4{(2-hydroxy-3-acryloxy)propoxyethoxy}phenyl]propane,9,9-bis[4-{(2-hydroxy-3-acryloxy)propoxy}phenyl]fluorene,9,9-bis[4{(2-hydroxy-3-acryloxy)propoxyethoxy}phenyl]fluorine, andreaction products of epoxy resins based on novolacs with (meth)acrylicacid.

Polyethers obtained from the reaction of the abovementioned polyols orpolyepoxides with the unsaturated compounds with a hydroxy group such as2-hydroxyethyl(meth)acrylate, vinyl alcohol can also be used ascomponent (a).

Also suitable as components (a) are the amides of identical ordifferent, unsaturated carboxylic acids with aromatic, cycloaliphaticand aliphatic polyamines having preferably 2 to 6, especially 2 to 4,amino groups. Examples of such polyamines are ethylenediamine, 1,2- or1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine,1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine,dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine,phenylenediamine, bisphenylenediamine, di-β-aminoethyl ether,diethylenetriamine, triethylenetetramine, di(β-aminoethoxy) ordi(β-aminopropoxy)ethane. Other suitable polyamines are polymers andcopolymers, preferably with additional amino groups in the side chain,and oligoamides having amino end groups. Examples of such unsaturatedamides are methylenebisacrylamide, 1,6-hexamethylenebisacrylamide,diethylenetriaminetrismethacrylamide, bis(methacrylamidopropoxy)ethane,β-methacrylamidoethyl methacrylate andN[(β-hydroxyethoxy)ethyl]acrylamide.

Other examples are unsaturated urethanes derived from a polyisocyanateand an unsaturated compound having a hydroxy group or from apolyisocyanate, a polyol and an unsaturated compound having a hydroxygroup.

Other examples are polyesters, polyamides, or polyurethanes havingethylenically unsaturated groups in the chain. Suitable unsaturatedpolyesters and polyamides are also derived, for example, from maleicacid and diols or diamines. Some of the maleic acid can be replaced byother dicarboxylic acids. The polyesters and polyamides may also bederived from dicarboxylic acids and ethylenically unsaturated diols ordiamines, especially from those with relatively long chains of, forexample 6 to 20 C atoms. Examples of polyurethanes are those composed ofsaturated or unsaturated diisocyanates and of unsaturated or,respectively, saturated diols.

Other suitable polymers with acrylate or methacrylate groups in the sidechains are, for example, solvent soluble or alkaline soluble polyimideprecursors, for example poly(amic acid ester) compounds, having thephotopolymerizable side groups either attached to the backbone or to theester groups in the molecule, i.e. according to EP 624826. Sucholigomers or polymers can be formulated optionally with reactivediluents, like polyfunctional (meth)acrylates In order to prepare highlysensitive polyimide precursor resists.

Further examples of the component a) are also polymers or oligomershaving at least one carboxyl function and at least two ethylenicallyunsaturated groups within the molecular structure, such as a resinobtained by the reaction of a saturated or unsaturated polybasic addanhydride with a product of the reaction of phenol or cresol novolacepoxy resin and an unsaturated monocarboxylic acid, for example,commercial products such as EB9696, UCB Chemicals; KAYARAD TCR1025,Nippon Kayaku Co., LTD. Examples of the polybasic acid anhydride aremaleic anhydride, succinic anhydride, itaconic anhydride, phthalicanhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,methyltetrahydrophathalic anhydride, glutaric anhydride, glutaconicanhydride, citraconic anhydride, diglycolic anhydride, iminodiaceticanhydride, 1,1-cyclopentanediacetic anhydride, 3,3-dimethylglutaricanhydride, 3-ethyl-3-methylglutaric anhydride, 2-phenylglutaricanhydride, homophthalic anhydride, trimellitic anhydride, chlorendicanhydride, pyromellitic dianhydride, benzophenone tetracarboxylic aciddianhydride, biphenyl tetracarboxylic acid dianhydride, andbiphenylether tetracarboxylic acid dianhydride.

Other examples are the products from the polycondensation reactionand/or addition reaction of the compound of formula (XIV) with one ormore abovementioned polybasic acid anhydrides.

wherein Y, is

R₂₀ is hydrogen or methyl,R₃₀ and R₄₀ independently of each other are hydrogen, methyl, Cl, or Br,M₂ is substituted or unsubstituted alkylene having 1 to 10 carbon atoms,x is 0 to 5, and y is 1 to 10.

A preferred photopolymerizable composition comprises as component (a) acompound having at least two ethylenically unsaturated bonds and atleast one carboxylic add group in the molecule, in particular a reactionproduct obtained by adding an epoxy group containing unsaturatedcompound to a part of the carboxyl groups of a carboxylic add groupcontaining polymer or a reaction product of the compound shown belowwith one or more polybasic acid anhydrides. Further preferred components(a) comprise a compound of the formula XIV.

Further examples are reaction products obtained by adding an epoxy groupcontaining unsaturated compound to a part of the carboxyl groups of acarboxylic acid group containing polymer. As the carboxylic acidcontaining polymer, the abovementioned binder polymers which areresulting from the reaction of an unsaturated carboxylic acid compoundwith one or more polymerizable compounds, for example, copolymers of(meth)acrylic add, benzyl (meth)acrylate, styrene and2-hydroxyethyl(meth)acrylate, copolymers of (meth)acrylic acid, styreneand α-methystyrene, copolymers of (meth)acrylic acid, N-phenylmalelmide,styrene and benzyl(meth)acrylate, copolymers of (meth)acrylic acid andstyrene, copolymers of (meth)acrylic add and benzyl(meth)acrylate,copolymers of tetrahydrofurfuryl(meth)acrylate, styrene and(meth)acrylic acid, and the like.

Examples of the unsaturated compounds having an epoxy group are givenbelow in the formula (V-1)-(V-15);

wherein R₅₀ is hydrogen or methyl group, M₃ is substituted orunsubstituted alkylene having 1 to 10 carbon atoms.

Among these compounds, compounds having alicyclic epoxy groups areparticularly preferred, because these compounds have a high reactivitywith carboxyl group-containing resins, accordingly the reaction time canbe shortened. These compounds further do not cause gelation in theprocess of reaction and make it possible to carry out the reactionstably. On the other hand, glycidyl acrylate and glycidyl methacrylateare advantageous from the viewpoint of sensitivity and heat resistancebecause they have a low molecular weight and can give a high conversionof esterification.

Concrete examples of the abovementioned compounds are, for example areaction product of a copolymer of styrene, α-methyl styrene and acrylicacid or a copolymer of methyl methacrylate and acrylic acid with3,4-epoxycyclohexylmethyl(meth)acrylate.

Unsaturated compounds having a hydroxy group such as2-hydroxyethyl(meth)acrylate and glycerol mono(meth)acrylate can be usedinstead of the above mentioned epoxy group containing unsaturatedcompounds as the reactant for carboxylic acid group containing polymers.

Other examples are half esters of anhydride containing polymers, forexample reaction products of a copolymer of maleic anhydride and one ormore other polymerizable compounds with (meth)acrylates having analcoholic hydroxy group such as 2-hydroxyethyl(meth)acrylate or havingan epoxy group for example such as the compounds described in theformula (V-1)-(V-15).

Reaction products of polymers having alcoholic hydroxy groups such ascopolymers of 2-hydroxyethyl(meth)acrylate, (meth)acrylic acid, benzymethacylate and styrene, with (meth)acrylic acid or (meth)acryl chloridecan also be used as component (a).

Other examples are reaction products of a polyester with terminalunsaturated groups, which is obtained from the reaction of a dibasicacid anhydride and a compound having at least two epoxy groups followedby further reaction with an unsaturated compound, with a polybasic acidanhydride.

Further examples are resins obtained by the reaction of a saturated orunsaturated polybasic acid anhydride with a reaction product obtained byadding epoxy group containing (meth)acrylic compound to all of thecarboxyl groups of a carboxylic acid containing polymer as mentionedabove.

The photopolymerizable compounds can be used alone or in any desiredmixtures.

In a color filter resist composition the whole amount of the monomerscontained in the photopolymerizable composition is preferably 5 to 80%by weight, in particular 10 to 70% by weight based on the whole solidcontents of the composition, i.e. the amount of all components withoutthe solvent(s).

As the binder used in the color filter resist composition, which issoluble in an alkaline aqueous solution and insoluble in water, forexample, a homopolymer of a polymerizable compound having one or moreacid groups and one or more polymerizable unsaturated bonds in themolecule, or a copolymer of two or more kinds thereof, and a copolymerof one or more polymerizable compounds having one or more unsaturatedbonds copolymerizable with these compounds and containing no add group,can be used. Such compounds can be obtained by copolymerizing one ormore kinds of a low molecular compound having one or more acid groupsand one or more polymerizable unsaturated bonds in the molecule with oneor more polymerizable compounds having one or more unsaturated bondscopolymerizable with these compounds and containing no acid group.Examples of adds groups are, a —COOH group, a —SO₃H group, a —SO₂NHCO—group, a phenolic hydroxy group, a —SO₂NH— group, and a —CO—NH—CO—group. Among those, a high molecular compound having a —COOH group isparticularly preferred.

Preferably, the organic polymer binder in the color filter resistcomposition comprises an alkali soluble copolymer comprising, asaddition polymerizable monomer units, at least an unsaturated organicacid compound such as acrylic acid, methacrylic acid and the like. It ispreferred to use as a further co-monomer for the polymer binder anunsaturated organic acid ester compound such as methyl acrylate,ethyl(meth)acrylate, benzyl(meth)acrylate, styrene and the like tobalance properties such as alkaline solubility, adhesion rigidity,chemical resistance etc.

The organic polymer binder can either be a random co-polymer or ablock-co-polymer, for example, such as described in U.S. Pat. No.5,368,976.

Examples of polymerizable compounds having one or more add group and oneor more polymerizable unsaturated bond in the molecule include thefollowing compounds:

Examples of the polymerizable compounds having one or more —COOH groupsand one or more polymerizable unsaturated bonds in a molecule are(meth)acrylic acid, 2-carboxyethyl (meth)acrylic acid,2-carboxypropyl(meth)acrylic acid, crotonic acid, cinnamic acid,mono[2-(meth)acryloyloxyethyl]succinate,mono[2-meth)acryloyloxyethyl]adipate,mono[2-(meth)acryloyloxyethyl]phthalate,mono[2-(meth)acryloyloxyethyl]hexahydrophthalate,mono[2-(meth)acryloyloxyethyl]maleate,mono[2-(meth)acryloyloxypropyl]succinate,mono[2-(meth)acryloyloxypropyl]adipate,mono[2-(meth)acryloyloxypropyl]phthalate,mono[2-(meth)acryloyloxypropyl]hexahydrophthalate,mono[2-(meth)acryloyloxypropyl]maleate,mono[2-(meth)acryloyloxybutyl]succinate,mono[2-(meth)acryloyloxybutyl]adipate,mono[2-(meth)acryloyloxybutyl]phthalate,mono[2-(meth)acryloyloxybutyl]hexahydrophthalate,mono[2-(meth)acryloyloxybutyl]maleate, 3-(alkylcarbamoyl)acrylic acid,α-chloroacrylic add, maleic acid, monoesterified maleic acid, fumaricacid, itaconic acid, citraconic acid, mesaconic acid, maleic anhydride,and ω-carboxypolycaprolactone mono(meth)acrylate.

Vinylbenzenesulfonic acid and 2-(meth)acrylamide-2-methylpropanesulfonicacid are examples of the polymerizable compounds having one or more—SO₃H groups and one or more polymerizable unsaturated bonds.

N-methylsulfonyl(meth)acrylamide, N-ethylsulfonyl(meth)acrylamide,N-phenylsulfanyl(meth)acrylamide, andN-p-methylphenylsulfonyl)(meth)acrylamide are examples of thepolymerizable compounds having one or more —SO₂NHCO— groups and one ormore polymerizable unsaturated bonds.

Examples of polymerizable compounds having one or more phenolic hydroxygroups and one or more polymerizable unsaturated bonds in a moleculeinclude hydroxyphenyl(meth)acrylamide, dihydroxyphenyl(meth)acrylamide,hydroxyphenylarbonyloxyethyl(meth)acrylate,hydroxyphenyloxyethyl(meth)acrylate,hydroxyphenylthloethyl(meth)acrylate,dihydroxyphenylcarbonyloxyethyl(meth)acrylate,dihydroxyphenyloxyethyl(meth)acrylate, anddihydroxy-phenylthioethyl(meth)acrylate.

Examples of the polymerizable compound having one or more —SO₂NH— groupsand one or more polymerizable unsaturated bonds in the molecule includecompounds represented by formula (a) or (b):CH═CHA₁-Y₁-A₂-SO₂—NH-A₃  (a)CH₂═CHA₄-Y₂-A₅-NH—SO₂-A₆  (b)wherein Y₁ and Y₂ each represents —COO—, —CONA₇-, or a single bond; A₁and A₄ each represents H or CH₃; A₂ and A₅ each representsC₁-C₁₂alkylene optionally having a substituent, cycloalkylene, arylene,or aralkylene, or C₂-C₁₂alkylene into which an ether group and athioether group are inserted, cycloalkylene, arylene, or aralkylene; A₃and A₆ each represents H, C₁-C₁₂alkyl optionally having a substituent, acycloalkyl group, an aryl group, or an aralkyl group; and A₇ representsH, C₁-C₁₂alkyl optionally having a substituent, a cycloalkyl group, anaryl group, or an aralkyl group.

The polymerizable compounds having one or more —CO—NH—CO— group and oneor more polymerizable unsaturated bond include maleimide andN-acryloyl-acrylamide. These polymerizable compounds become the highmolecular compounds comprising a —CO—NH—CO— group, in which a ring isformed together with a primary chain by polymerization. Further, amethacrylic add derivative and an acrylic acid derivative each having a—CO—NH—CO— group can be used as well. Such methacrylic acid derivativesand the acrylic acid derivatives include, for example, a methacrylamidederivative such as N-acetylmethacrylamide, N-propionylmethacrylamide,N-butanoylmethacrylamide, N-pentanoylmethacrylamide,N-decanoylmethacrylamide, N-dodecanoylmethacrylamide,N-benzoylmethacrylamide, N-(p-methylbenzoyl)methacryl-amide,N-(p-chlorobenzoyl)methacrylamide, N-(naphthyl-carbonyl)methacrylamide,N-(phenylacetyl)-methacryl-amide, and 4-methacryloylaminophthalimide,and an acrylamide derivative having the same substituent as these. Thesepolymerizable compounds polymerize to be compounds having a —CO—NH—CO—group in a side chain.

Examples of polymerizable compounds having one or more polymerizableunsaturated bond and containing no acid group include a compound havinga polymerizable unsaturated bond, selected from esters of (meth)acrylicacid, such as methyl(meth)acrylate, ethyl(meth)acrylate,propyl(meth)acrylate, butyl(meth)acrylate,tetrahydrofurfuryl(meth)acrylate, benzyl(meth)acrylate,2-ethylhexyl(meth)acrylate, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, glycerolmono(meth)acrylate, dihydroxypropyl(meth)acrylate, alkyl(meth)acrylate,cyclohexyl(meth)acrylate, phenyl(meth)acrylate,methoxyphenyl(meth)acrylate, methoxyethyl(meth)acrylate,phenoxyethyl(meth)acrylate, methoxydiethyleneglycol(meth)acrylate,methoxytriethyleneglycol(meth)acrylate, methoxypropyl(meth)acrylate,methoxydipropyleneglycol(meth)acrylate, isobornyl meth(acrylate),dicyclopentadienyl(meth)acrylate,2-hydroxy-3-phenoxypropyl(meth)acrylate,tricyclo[5.2.1.0^(2,6)]-decan-8-yl(meth)acrylate,aminoethyl(meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate,aminopropyl(meth)acrylate, N,N-dimethylaminopropyl(meth)acrylate,glycidyl(meth)acrylate, 2-methylglycidyl(meth)acrylate,3,4-epoxybutyl(meth)acrylate, 6,7-epoxyheptyl(meth)acrylate; vinylaromatic compounds, such as styrene, α-methylstyrene, vinyltoluene,p-chlorostyrene, polychlorostyrene, fluorostyrene, bromostyrene,ethoxymethyl styrene, methoxystyrene, 4-methoxy-3-methystyrene,dimethoxystyrene, vinylbenzyl methyl ether, vinylbenzyl glycidyl ether,indene, 1-methylindene; vinyl or allyl esters, such as vinyl acetate,vinyl propionate, vinyl butylate, vinyl pivalate, vinyl benzoate, vinyltrimethylacetate, vinyl diethylacetate, vinyl barate, vinyl caproate,vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinylbutoxyacetate, vinyl phenylacetate, vinyl acetate, vinyl acetoacetate,vinyl lactate, vinyl phenylbutylate, vinyl cyclohexylcarboxylate, vinylsalicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinylnaphthoate, allyl acetate, allyl propionate, allyl butylate, allylpivalate, allyl benzoate, allyl caproate, allyl stearate, allylacetoacetate, allyl lactate; vinyl or allyl ethers, such as vinyl methylether, vinyl ethyl ether, vinyl hexyl ether, vinyl octyl ether, vinylethylhexyl ether, vinyl methoxyethyl ether, vinyl ethoxyethyl ether,vinyl chloroethyl ether, vinyl hydroxyethyl ether, vinyl ethybutylether, vinyl hydroxyethoxyethyl ether, vinyl dimethylaminoethyl ether,vinyl diethylaminoethyl ether, vinyl butylaminoethyl ether, vinyl benzylether, vinyl tetrahydrofurfuryl ether, vinyl phenyl ether, vinyl tolylether, vinyl chlorophenyl ether, vinyl chloroethyl ether, vinyldichlorophenyl ether, vinyl naphthyl ether, vinyl anthryl ether, allylglycidyl ether, amide type unsaturated compounds, such as(meth)acrylamide, N,N-dimethyl(meth)acrylamide,N,N-diethyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide,N,N-diethylhexyl(meth)acrylamide, N,N-dicyclohexyl (meth)acrylamide,N,N-diphenyl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide,N-hydroxyethyl-N-methyl(meth)acrylamide, N-methyl(meth)acrylamide,N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide,N-butyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide,N-heptyl(meth)acrylamide, N-octyl(meth)acrylamide,N-ethyhexyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamidecyclohexyl,N-benzyl(meth)acrylamide, N-phenyl(meth)acrylamide,N-tolyl(meth)acrylamide, N-hydroxyphenyl(meth)acrylamide,N-naphthyl(meth)acrylamide, N-phenylsulfonyl(meth)acrylamide,N-methylphenylsulfonyl(meth)acrylamide and N-(meth)acryloylmorpholine,diacetone acrylamide, N-methylol acrylamide, N-butoxyacrylamide;polyolefin type compounds, such as butadiene, isoprene, chloroprene andthe like; (meth)acrylonitrile, methyl isopropenyl ketone, maleimide,N-phenylmaleimide, N-methylphenylmaleimide, N-methoxyphenylmaleimide,N-cyclohexylmaleimide, N-alkylmaleimide, maleic anhydride, polystyrenemacromonomer, polymethyl (meth)acrylate macromonomer,polybutyl(meth)acrylate macromonomer; crotonates, such as butylcrotonate, hexyl crotonate, glycerine monocrotonate; and itaconates,such as dimethyl itaconate, diethyl itaconate, dibutyl itaconate; andmaleates or fumarates, such as dimethyl mareate, dibutyl fumarate.

Preferable examples of copolymers are copolymers of methyl(meth)acrylateand (meth)acrylic acid, copolymers of benzyl(meth)acrylate and(meth)acrylic acid, copolymers of methyl(meth)acrylate/,ethyl(meth)acrylate and (meth)acrylic add, copolymers of benzyl(meth)acrylate, (meth)acrylic acid and styrene, copolymers ofbenzyl(meth)acrylate, (meth)acrylic acid and2-hydroxyethyl(meth)acrylate, copolymers of methyl(meth)acrylate/, butyl(meth)acrylate, (metha)crylic acid and styrene, copolymers ofmethyl(meth)acrylate, benzyl (meth)acrylate, (meth)acrylic acid andhydroxyphenyl(meth)acrylate, copolymers of methyl (meth)acrylate,(metha)crylic acid and polymethyl(meth)acrylate macromonomer, copolymersof benzyl(meth)crylate, (metha)crylic acid and polymethyl(meth)acrylatemacromonomer, copolymers of tetrahydrofurfuryl(meth)acrylate, styreneand (meth)acrylic acid, copolymers of methyl(meth)acrylate,(meth)acrylic acid and polystyrene macromonomer, copolymers ofbenzyl(meth)acrylate, (meth)acrylic acid and polystyrene macromonomer,copolymers of benzyl(meth)acrylate, (meth)acrylic acid,2-hydroxyethyl(meth)acrylate and polystyrene macromonomer, copolymers ofbenzyl(meth)acrylate, (meth)acrylic add, 2-hydroxypropyl(meth)acrylateand polystyrene macromonomer, copolymers of benzyl (meth)acrylate,(meth)acrylic acid, 2-hydroxy-3-phenoxypropyl(meth)acrylate andpolymethyl (meth)acrylate macromonomer, copolymers ofmethyl(meth)acrylate, (meth)acrylic acid, 2-hydroxyethyl(meth)acrylateand polystyrene macromonomer, copolymers of benzyl(meth)acrylate,(metha)crylic acid, 2-hydroxyethyl(meth)acrylate andpolymethyl(meth)acrylate macromonomer, copolymers of N-phenylmaleimide,benzyl(meth)acrylate, (metha)crylic acid and styrene, copolymers ofbenzyl(meth)acrylate, (meth)acrylic acid, N-phenylmaleimide,mono-[2-(meth)acryloyloxyethyl]succinate and styrene, copolymers ofallyl(meth)acrylate, (meth)acrylic acid, N-phenylmaleimide,mono-[2-(meth)acryloyloxyethyl]succinate and styrene, copolymers ofbenzyl(meth)acrylate, (meth)acrylic acid, N-phenylmaleimide, glycerolmono(meth)acrylate and styrene, copolymers of benzyl(meth)acrylate,ω-carboxypolycaprolactone mono(meth)acrylate, (meth)acrylic acid,N-phenylmaleimide, glycerol mono(meth)acrylate and styrene, an dcopolymers of benzyl(meth)acrylate, (meth)acrylic add,N-cyclohexylmaleimide and styrene.

There can be used as well hydroxystyrene homo- or co-polymers or anovolak type phenol resin, for example, poly(hydroxystyrene) andpoly(hydroxystyrene-co-vinylcyclohexanol), a novolak resin, a cresolnovolak resin, and a halogenated phenol novolak resin. Morespecifically, it includes, for example, the methacrylic acid copolymers,the acrylic acid copolymers, the itaconic acid copoymers, the crotonicacid copolymers, the maleic anhydride co-polymers, for example, withstyrene as a co-monomer, and maleic acid copolymers, and partiallyesterified maleic acid copolymers each described in, for example, JP59-44615-B4 (the term “JP-B4” as used herein refers to an examinedJapanese patent publication), JP 54-34327-B4, JP 58-12577-B4, and JP54-25957-B4, JP 59-53836-A, JP 59-71048-A, JP 60-159743-A, JP60-258539-A, JP 1-152449-A, JP 2-199403-A, and JP 2-199404-A, and whichcopolymers can be further reacted with an amine, as e.g disclosed inU.S. Pat. No. 5,650,263; further, a cellulose derivative having acarboxyl group on a side chain can be used, and particularly preferredare copolymers of benzyl(meth)acrylate and (meth)acrylic add andcopolymers of benzyl(meth)acrylate, (meth)acrylic acid and othermonomers, for example as described in U.S. Pat. No. 4,139,391, JP59-44615-B4, JP 60-159743-A and JP 60-258539-A.

With respect to those having carboxylic acid groups among the aboveorganic binder polymers, it is possible to react some or all of thecarboxylic acid groups with glycidyl(meth)acrylate or anepoxy(meth)acrylate to obtain photopolymerizable organic binder polymersfor the purpose of improving the photosensitivity, coating filmstrength, the coating solvent and chemical resistance and the adhesionto the substrate. Examples are disclosed in, JP 50-34443-B4 and JP50-34444-B4, U.S. Pat. No. 5,153,095, by T. Kudo et al. in J. Appl.Phys., Vol. 37 (1998), p. 3594-3603, U.S. Pat. No. 5,677,385, and U.S.Pat. No. 5,650,233.

The weight-average molecular weight of the binders is preferably 500 to1,000,000, e.g. 3,000 to 1,000,000, more preferably 5,000 to 400,000.

These compounds may be used singly or as a mixture of two or more kinds.The content of the binder in the light-sensitive resin composition ispreferably 10 to 95 weight %, more preferably 15 to 90 weight % based onthe whole solid matters.

Further, in the color filter the total solid component of each color maycontain an ionic impurity-scavenger, e.g. an organic compound having anepoxy group. The concentration of the ionic impurity scavenger in thetotal solid component generally is in the range from 0.1% by weight to10% by weight.

Examples of color filters, especially with respect to the abovedescribed combinations of pigments and ionic impurity scavenger aregiven in EP 320264. It is understood, that the photoinitiators accordingto the present invention, i.e. the compounds of the formulae I, II, andIII in the color filter formulations described in EP 320264 can replacethe triazine initiator compounds.

The compositions according to this invention can comprise additionally acrosslinking agent which is activated by an acid, for example asdescribed in JP 10 221843-A, and a compound which generates acidthermally or by actinic radiation and which activates a crosslinkingreaction.

The compositions according to this invention can also comprise latentpigments which are transformed into finely dispersed pigments during theheat treatment of the latent pigment containing photosensitive patternor coating. The heat treatment can be performed after exposure or afterdevelopment of the latent pigment-containing photoimageable layer. Suchlatent pigments are soluble pigment precursors which can be transformedinto insoluble pigments by means of chemical, thermal, photolytic orradiation induced methods as described, for example, in U.S. Pat. No.5,879,855. This transformation of such latent pigments can be enhancedby adding a compound which generates acid at actinic exposure or byadding an acidic compound to the composition. Therefore, a color filterresist can also be prepared, which comprises a latent pigment in acomposition according to this invention.

Examples for color filter resists, the composition of such resists andthe processing conditions are given by T. Kudo et al., Jpn. J. Appl.Phys. Vol. 37 (1998) 3594; T. Kudo et al., J. Photopolym. Sd. Technol.Vol 9 (1996) 109; K. Kobayashi, Solid State Technol. November 1992, p.S15-S18; U.S. Pat. No. 5,368,976; U.S. Pat. No. 5,800,952; U.S. Pat. No.5,882,843; U.S. Pat. No. 5,879,855; U.S. Pat. No. 5,866,298; U.S. Pat.No. 5,863,678; JP 06-230212-A; EP 320264; JP 09-269410-A; JP10-221843-A; JP 01-090516-A; JP 10-171119-A, U.S. Pat. No. 5,821,016,U.S. Pat. No. 5,847,015, U.S. Pat. No. 5,882,843, U.S. Pat. No.5,719,008, EP 881541, or EP 902327.

The photoinitiators of the present invention can be used in color filterresists, for example, such as those given as examples above, or canpartially or fully replace the known photoinitiators in such resists. Itis understood by a person skilled in the art that the use of the newphotoinitiators of the present invention is not limited to the specificbinder resins, crosslinkers and formulations of the color filter resistexamples given hereinbefore but can be used in conjunction with anyradically polymerizable component in combination with a dye or colorpigment or latent pigment to form a photosensitive color filter ink orcolor filter resist.

Accordingly, subject of the invention also is a color filter prepared byproviding red, green and blue (RGB) colour elements and, optionally ablack matrix, all comprising a photosensitive resin and a pigment on atransparent substrate and providing a transparent electrode either onthe surface of the substrate or on the surface of the color filterlayer, wherein said photosensitive resin comprises a polyfunctionalacrylate monomer, an organic polymer binder and a photopolymerizationinitiator of formula I, II or III as described above. The monomer andbinder components, as well as suitable pigments are as described above.In the manufacture of color filters the transparent electrode layer caneither be applied on the surface of the transparent substrate or can beprovided on the surface of the red, green and blue picture elements andthe black matrix. The transparent substrate is for example a glasssubstrate which can additionally have an electrode layer on its surface.

It is preferred to apply a black matrix between the color areas ofdifferent color in order to improve the contrast of a color filter.

Instead of forming a black matrix using a photosensitive composition andpatterning the black photosensitive composition photolithographically bypatternwise exposure (i.e. through a suitable mask) to form the blackpattern separating the red green and blue coloured areas on thetranparent substrate it is alternatively possible to use an inorganicblack matrix. Such inorganic black matrix can be formed from deposited(i.e. sputtered) metal (i.e. chromium) film on the transparent substrateby a suitable imaging process, for example utilizing photolithographicpatterning by means of an etch resist, etching the inorganic layer inthe areas not protected by the etch resist and then removing theremaining etch resist.

There are different methods known how and at which step in the colorfilter manufacturing process the black matrix can be applied. It caneither be applied directly on the transparent substrate prior toformation of the red, green and blue (RGB) colour filter as alreadymentioned above, or it can be applied after the RGB colour filter isformed on the substrate.

In a different embodiment of a color filter for a liqid crystal display,according to U.S. Pat. No. 5,626,796, the black matrix can also beapplied on the substrate opposite to the RGB color filterelement-carrying substrate, which is separated from the former by aliquid crystal layer.

If the transparent electrode layer is deposited after applying the RGBcolor filter elements and—optionally—the black matrix, an additionalovercoat film as aprotective layer can be applied on the color filterlayer prior to deposition of the electrode layer, for example, asdescribed in U.S. Pat. No. 5,650,263.

To form an overcoat layer of a color filter, photosensitive resin orthermosetting resin compositions are employed. The photosensitivecomposition of the present invention can also be used to form suchovercoat layers, because a cured film of the composition is excellent inflatness, hardness, chemical and thermal resistance, transparencyespecially in a visible region, adhesion to a substrate, and suitabilityfor forming a transparent conductive film, e.g., an ITO film, thereon.In the production of a protective layer, there has been a demand thatunnecessary parts of the protective layer, for example on scribing linesfor cutting the substrate and on bonding pads of solid image sensorsshould be removed from the substrate as described in JP57-42009-A,JP1-130103-A and JP1-134306-A. In this regard, it is difficult toselectively form a protective layer with good precision using theabove-mentioned thermosetting resins. The photosensitive composition,however, allows to easily remove the unnecessary parts of the protectivelayer by photolithography.

It is obvious to those skilled in the art, that the photosensitivecompositions of the present invention can be used for generating red,green and blue color pixels and a black matrix, for the manufacture of acolor filter, regardless of the above described differences inprocessing, regardless, of additional layers which can be applied andregardless of differences in the design of the color filter. The use ofa composition according to the present invention to form coloredelements shall not be regarded as limited by different designs andmanufacturing processes of such color filters.

The photo-sensitive composition of the present invention can suitably beused for forming a color filter but will not be limited to thisapplication. It is useful as well for a recording material, a resistmaterial, a protective layer, a dielectric layer, in displayapplications and display elements, a paint, and a printing ink.

The photosensitive compositions according to the invention are alsosuitable for manufacturing interlayer insulating layers or dielectriclayers in a liquid crystal display, and more particularly in areflection type liquid crystal display including an active matrix typedisplay having a thin film transistor (TFT) as a switching device, and apassive matrix type without a switching device.

In recent years, liquid crystal displays have, for example, been widelyused for pocket-type TV sets and terminal devices for communication byvirtue of its small thickness and light weight. A reflection type liquidcrystal display without necessity of using a back light is in particularin demand because it is ultra-thin and light-weight, and it cansignificantly reduce power consumption. However, even if a back light isremoved out of a presently available transmission type color liquidcrystal display and a light reflection plate is added to a lower surfaceof the display, it would cause a problem in that the efficiency ofutilizing lights is low, and it is not possible to have practicalbrightness.

As a solution to this problem, there have been suggested variousreflection type liquid crystal displays for enhancing an efficiency ofutilizing lights. For instance, a certain reflection type liquid crystaldisplay is designed to include a pixel electrode having reflectionfunction.

The reflection type liquid crystal display includes an insulatingsubstrate and an opposing substrate spaced away from the insulatingsubstrate. A space between the substrates is filled with liquidcrystals. A gate electrode is formed on the insulating substrate, andboth the gate electrode and the insulating substrate are covered with agate insulating film. A semiconductor layer is then formed on the gateinsulating film above the gate electrode. A source electrode and a drainelectrode are also formed on the gate insulating film in contact withthe semiconductor layer. The source electrode, the drain electrode, thesemiconductor layer, and the gate electrode cooperate with one anotherto thereby constitute a bottom gate type TFT as a switching device.

An interlayer insulating film is formed covering the source electrode,the drain electrode, the semiconductor layer, and the gate insulatingfilm therewith. A contact hole is formed throughout the interlayerinsulating film on the drain electrode. A pixel electrode made ofaluminum is formed on both the interlayer insulating film and an innersidewall of the contact hole. The drain electrode of the TFT iseventually in contact with the pixel electrode through the interlayerinsulating film. The interlayer insulating layer is generally designedto have a roughened surface by which the pixel electrode acts as areflection plate which diffuses lights to get a wider angle for viewing(angle of visibility).

The reflection type liquid crystal display remarkably enhances anefficiency of using lights by virtue that the pixel electrode acts as alight reflection plate.

In the above-mentioned reflection type liquid crystal display, theinterlayer insulating film is designed to have projections and recessesby photolithography. To form and control a fine shape of the projectionsand recesses in micrometer order for surface roughness and to formcontact holes, photolithography methods using positive and negativephotoresists are used. For these resists the compositions according tothe invention are especially suitable.

The photosensitive compositions according to the Invention can furtherbe used for manufacturing spacers, which control a cell gap of theliquid crystal part in liquid crystal display panels. Since theproperties of light transmitted or reflected through the liquid crystallayer in a liquid crystal display are dependent on the cell gap, thethickness accuracy and uniformity over the pixel array are criticalparameters for the performance of the liquid crystal display unit. In aliquid crystal cell, the spacing between the substrates in the cell ismaintained constant by sparsely distributing glass or polymer spheresabout several micrometers in diameter as spacers between the substrates.The spacers are thus held between the substrates to maintain thedistance between the substrates at a constant value. The distance isdetermined by the diameter of the spacers. The spacers assure theminimum spacing between the substrates; i.e., they prevent a decrease indistance between the substrates. However, they cannot prevent thesubstrates from being separated apart from each other, i.e., theincrease in distance between the substrates. Additionally, this methodof using spacer beads has problems of the uniformity in the diameter ofspacer beads and difficulty in the even dispersion of spacer beads onthe panel, as well as nonuniform orientation and decrease in brightnessand/or optical aperture depending on the location of spacers on pixelarray region. Liquid crystal displays having a large image display areahave recently been attracting much attention. However, the increase inthe area of a liquid crystal cell generally produces the distortion ofthe substrates constituting the cell. The layer structure of the liquidcrystal tends to be destroyed due to the deformation of the substrate.Thus, even when spacers are used for maintaining the spacing between thesubstrates constant, a liquid crystal display having a large imagedisplay area is unfeasible because the display experiences disturbances.Instead of the above spacer sphere dispersion method, a method offorming columns in the cell gap as spacers has been proposed. In thismethod, columns of a resin are formed as spacers in the region betweenthe pixel array region and the counter electrode to form a prescribedcell gap. Photosensitive materials having adhesive properties withphotolithography are commonly used, for instance, in the manufacturingprocess of color filters. This method is advantageous compared with theconventional method using spacer beads in the points that location,number and height of the spacers may be controlled freely. In a colorliquid crystal display panel, such spacers are formed in the nonimagingarea under black matrix of color filter elements. Therefore, the spacersformed using photosensitive compositions do not decrease brightness andoptical aperture.

Photosensitive compositions for producing protective layer with spacersfor color filters are disclosed in JP 200041701-A and dry film typephotoresists for spacer materials are also disclosed in JP 11-174459-Aand JP 11-174464-A. As described in the documents, the photosensitivecompositions, liquid and dry film photoresists, are comprising at leastan alkaline or acid soluble binder polymer, a radically polymerizablemonomer, and a radical initiator. In some cases, thermally crosslinkablecomponents such as epoxide and carboxylic acid may additionally beincluded.

The steps to form spacers using a photosensitive composition are asfollows:

a photosensitive composition is applied to the substrate, for instance acolor filter panel and after the substrate is prebaked, it is exposed tolight through a mask. Then, the substrate is developed with a developerand patterned to form the desired spacers. When the composition containssome thermosetting components, usually a postbaking is carried out tothermally cure the composition.

The photocurable compositions according to the invention are suitablefor producing spacers for liquid crystal displays (as described above)because of their high sensitivity.

The photosensitive compositions according to the invention are alsosuitable for manufacturing microlens arrays used in liquid crystaldisplay panels, image sensors and the like.

Microlenses are microscopic passive optical components that fit onactive optoelectronic devices such as detectors, displays, and lightemitting devices (light-emitting diodes, transversal and vertical cavitylasers) to improve their optical input or output quality. The areas ofapplications are wide and cover areas such as telecommunications,information technology, audio-visual services, solar cells, detectors,solid-state light sources, and optical interconnects. Present opticalsystems use a variety of techniques to obtain efficient coupling betweenmicrolenses and microoptical devices.

The microlens arrays are used for condensing illuminating light on thepicture element regions of a nonluminescent display device, such as aliquid crystal display devices, to increase the brightness of thedisplay, for condensing incident light or as a means for forming animage on the photoelectric conversion regions of a line image sensorused for example in facsimiles and the like to improve the sensitivityof these devices, and for forming an image to be printed on aphotosensitive means used in liquid crystal printers or light emittingdiode (LED) printers.

The most common application is their use to improve the efficiency ofphotodetector arrays of a solid-state image sensing device such as acharge coupled device (CCD). In a detector array, the collection of asmuch light as possible in each detector element or pixel is wanted. If amicrolens is put on top of each pixel, the lens collects incoming lightand focuses ft onto an active area that is smaller than the size of thelens.

According to the prior-art, microlens arrays can be produced by avariety of methods;

(1) A method for obtaining convex lenses wherein a pattern of the lensesin a planar configuration is drawn on a thermoplastic resin by aconventional photolithographic technique or the like, and then thethermoplastic resin is heated to a temperature above the softening pointof the resin to have flowability, thereby causing a sag in the patternedge (so called “reflowing”) (see, e.g., JP 60-38989-A, JP 60-165623-A,JP 61-67003-A, and JP 2000-39503-A). In this method, when thethermoplastic resin used is photosensitive, a pattern of the lenses canbe obtained by exposure of this resin to light.

(2) A method for forming a plastic or glass material by the use of amold or a stamper. As lens material, a photocurable resin and athermosetting resin can be used in this method (see, e.g., WO99/38035).

(3) A method for forming convex lenses on the basis of a phenomenon inwhich when a photosensitive resin is exposed to light in a desiredpattern by the use of an aligner, unreacted monomers move from theunexposed regions to the exposed regions, resulting in a swell of theexposed regions (see, e.g., Journal of the Research Group in MicroopticsJapanese Society of Applied Physics, Colloquium in Optics, Vol. 5, No.2, pp. 118-123 (1987) and Vol. 6, No. 2, pp. 87-92(1988)).

On the upper surface of a supporting substrate, a photosensitive resinlayer is formed. Thereafter, with the use of a separate shading mask,the upper surface of the photosensitive resin layer is illuminated withlight from a mercury lamp or the like, so that the photosensitive resinlayer is exposed to the light. As a result, the exposed portions of thephotosensitive resin layer swell into the shape of convex lenses to formthe light condensing layer having a plurality of microlens.

(4) A method for obtaining convex lenses wherein a photosensitive resinis exposed to light by a proximity exposure technique in which aphotomask is not brought into contact with the resin, to cause a blur atthe pattern edge, so that the amount of photochemical reaction productsis distributed depending upon the degree of blurring at the pattern edge(see, e.g., JP 61-153602-A).

(5) A method for generating a lens effect wherein a photosensitive resinis exposed to light with a particular intensity distribution to form adistribution pattern of refractive index depending upon the lightintensity (see, e.g., JP 60-72927-A and JP 60-166946-A).

The photosensitive compositions according to the invention can be usedin any one of the above-mentioned methods to form microlens arrays usingphotocurable resin compositions.

A particular class of techniques concentrates on forming microlenses inthermoplastic resins like photoresist. An example is published byPopovic et al. in the reference SPIE 898, pp. 23-25 (1988). Thetechnique, named reflow technique, comprises the steps of defining thelenses' footprint in a thermoplastic resin, e.g. by photolithography ina photosensitive resin like a photoresist, and subsequently heating thismaterial above its reflow temperature. The surface tension draws theisland of photoresist into a spherical cap with a volume equal to theoriginal island before the reflow. This cap is a plano-convex microlens.Advantages of the technique are, amongst others, the simplicity, thereproducibility, and the possibility of integration directly on top of alight-emitting or light-detecting optoelectronic device.

In some cases, an overcoat layer is formed on the patterned lens unitswith a rectangular shape prior to reflowing to avoid a sagging of theisland of the resin in the middle without reflow into a spherical cap inthe reflow step. The overcoat acts as a permanent protective layer. Thecoating layer is also made of a photosensitive composition.

Microlens arrays can also be fabricated by the use of a mold or astamper as, for example, disclosed in EP0932256A2. A process ofmanufacturing the planar microlens array is as follows: a release agentis coated on a shaping surface of a stamper on which convex portions aredensely arranged, and a photocurable synthetic resin material having ahigh refractive index is set on the shaping surface of the stamper.Next, the base glass plate is pushed onto the synthetic resin material,thereby spreading the synthetic resin material, and the synthetic resinmaterial is cured by irradiating with ultraviolet radiation or byheating and is shaped to form the convex microlenses. Thereafter thestamper is peeled off. Then, a photocurable synthetic resin materialhaving a low refractive index is additionally coated onto the convexmicrolenses as an adhesive layer and a glass substrate which is madeinto a cover glass plate is pushed onto the synthetic resin material,thereby spreading the same. The synthetic resin material is then curedand finally the planar microlens array is formed.

As disclosed in U.S. Pat. No. 5,969,867, a similar method using a moldis applied for the production of a prism sheet, which is used as a partof backlight units for color liquid crystal display panels to enhancethe brightness. A prism sheet forming a prism row on one side is mountedon the light-emitting surface of the backlight. For fabricating a prismsheet, an active energy ray-curable composition is cast and spread in alens mold which is made of metal, glass or resin and forms the lensshape of the prism row, etc., after which a transparent substrate sheetis placed onto it and active energy rays from an active energyray-emitting source are irradiated through the sheet for curing. Theprepared lens sheet is then released from the lens mold to obtain thelens sheet

The active energy ray-curable composition used to form the lens sectionmust have a variety of properties, including adhesion to the transparentsubstrate, and suitable optical characteristics.

Lenses at least with some photoresists in the prior art are notdesirable for some applications since the optical transmittance in theblue end of the optical spectrum is poor.

Because the photocurable compositions according to the invention havelow yellowing properties, both thermally and photochemically, they aresuitable for the production of microlens arrays as described above.

The novel radiation-sensitive compositions are also suitable forphotolithographic steps used in the production process of plasma displaypanels (PDP), particularly for the imaging forming process of barrierrib, phosphor layer and electrodes.

The PDP is a planar display for displaying images and information byvirtue of the emission of light by gas discharge. By the construction ofpanel and the method of operation, it is known in two types, i.e. DC(direct current) type and AC (alternating current) type.

By way of example, the principle of the DC type color PDP will bebriefly explained. In the DC type color PDP, the space interveningbetween two transparent substrates (generally glass plates) is dividedinto numerous minute cells by latticed barrier ribs interposed betweenthe transparent substrates. In the individual cells a discharge gas,such as He or Xe, is sealed. On the rear wall of each cell there is aphosphor layer which, on being excited by the ultraviolet lightgenerated by the discharge of the discharge gas, emits visible light ofthree primary colors. On the inner faces of the two substrates,electrodes are disposed as opposed to each other across the relevantcells. Generally, the cathodes are formed of a film of transparentelectroconductive material such as NESA glass. When a high voltage isapplied between these electrodes formed on the fore wall and the rearwall, the discharge gas which is sealed in the cells induces plasmadischarge and, by virtue of the ultraviolet light radiated consequently,incites the fluorescent elements of red, blue, and green colors to emitlights and effect the display of an image. In the full-color displaysystem, three fluorescent elements severally of the three primary colorsof red, blue, and green mentioned above jointly form one pictureelement.

The cells in the DC type PDP are divided by the component barrier ribsof a lattice, whereas those in the AC type PDP are divided by thebarrier ribs which are arranged parallel to each other on the faces ofthe substrates. In either case, the cells are divided by barrier ribs.These barrier ribs are intended to confine the luminous discharge withina fixed area to preclude false discharge or cross talk between adjacentdischarge cells and ensure ideal display.

The compositions according to the invention also find application forthe production of one- or more-layered materials for the image recordingor image reproduction (copies, reprography), which may be mono- orpolychromatic. Furthermore the materials are suitable for color proofingsystems. In this technology formulations containing microcapsules can beapplied and for the image production the radiation curing can befollowed by a thermal treatment. Such systems and technologies and theirapplications are for example disclosed in U.S. Pat. No. 5,376,459.

Photocuring is of great importance for printings, since the drying timeof the ink is a critical factor for the production rate of graphicproducts, and should be in the order of fractions of seconds. UV-curableinks are particularly important for screen printing and offset inks.

As already mentioned above, the novel mixtures are highly suitable alsofor producing printing plates. This application uses, for example,mixtures of soluble linear polyamides or styrene/butadiene and/orstyrene/isoprene rubber, polyacrylates or polymethyl methacrylatescontaining carboxyl groups, polyvinyl alcohols or urethane acrylateswith photopolymerizable monomers, for example acrylamides and/ormethacrylamides, or acrylates and/or methacrylates, and aphotoinitiator. Films and plates of these systems (wet or dry) areexposed over the negative (or positive) of the printed original, and theuncured parts are subsequently washed out using an appropriate solventor aqueous solutions.

Another field where photocuring is employed is the coating of metals, inthe case, for example, of the coating of metal plates and tubes, cans orbottle caps, and the photocuring of polymer coatings, for example offloor or wall coverings based on PVC.

Examples of the photocuring of paper coatings are the colourlessvarnishing of labels, record sleeves and book covers.

Also of interest is the use of the novel photoinitiators for curingshaped articles made from composite compositions. The composite compoundconsists of a self-supporting matrix material, for example a glass fibrefabric, or alternatively, for example, plant fibres [cf. K.-P. Mieck, T.Reussmann in Kunststoffe 85 (1995), 366-370], which is impregnated withthe photocuring formulation. Shaped parts comprising compositecompounds, when produced using the novel compounds, attain a high levelof mechanical stability and resistance. The novel compounds can also beemployed as photocuring agents in moulding, impregnating and coatingcompositions as are described, for example, in EP 7086. Examples of suchcompositions are gel coat resins, which are subject to stringentrequirements regarding curing activity and yellowing resistance, andfibre-reinforced mouldings, for example, light diffusing panels whichare planar or have lengthwise or crosswise corrugation. Techniques forproducing such mouldings, such as hand lay-up, spray lay-up, centrifugalcasting or filament winding, are described, for example, by P. H. Seldenin “Glasfaserverstärkte Kunststoffe”, page 610, Springer VerlagBerlin-Heidelberg-New York 1967. Examples of articles which can beproduced by these techniques are boats, fibre board or chipboard panelswith a double-sided coating of glass fibre-reinforced plastic, pipes,containers, etc. Further examples of moulding, impregnating and coatingcompositions are UP resin gel coats for mouldings containing glassfibres (GRP), such as corrugated sheets and paper laminates. Paperlaminates may be based on urea resins or melamine resins. Prior toproduction of the laminate, the gel coat is produced on a support (forexample a film). The novel photocurable compositions can also be usedfor casting resins or for embedding articles, for example electroniccomponents, etc.

The compositions and compounds according to the invention can be usedfor the production of holographies, waveguides, optical switches whereinadvantage is taken of the development of a difference in the index ofrefraction between irradiated and unirradiated areas.

The use of photocurable compositions for imaging techniques and for theoptical production of information carriers is also important. In suchapplications, as already described above, the layer (wet or dry) appliedto the support is irradiated imagewise, e.g. through a photomask, withUV or visible light, and the unexposed areas of the layer are removed bytreatment with a developer. Application of the photocurable layer tometal can also be carried out by electrodeposition. The exposed areasare polymeric through crosslinking and are therefore insoluble andremain on the support. Appropriate colouration produces visible images.Where the support is a metallized layer, the metal can, followingexposure and development, be etched away at the unexposed areas orreinforced by electroplating. In this way it is possible to produceelectronic circuits and photoresists. When used in image-formingmaterials the novel photoinitiators provide excellent performance ingenerating so called printout images, whereby a color change is induceddue to irradiation. To form such printout images different dyes and/ortheir leuco form are used and examples for such print out image systemscan be fount e.g. in WO 96/41240, EP 706091, EP 511403, U.S. Pat. No.3,579,339, and U.S. Pat. No. 4,622,286.

The novel photoinitiator is also suitable for a photopatternablecomposition for forming a dielectric layer of a multilayer layer circuitboard produced by a sequential build-up process.

The invention, as described above, provides compositions for producingpigmented and nonpigmented paints and varnishes, powder coatings,printing inks, printing plates, adhesives, dental compositions, puttymaterials, gel coats, photoresists for electronics like electroplatingresist, etch resist, both liquid and dry films, solder resist, asresists to manufacture color filters for a variety of displayapplications or to generate structures in the manufacturing processes ofplasma-display panels (e.g. barrier rib, phosphor layer, electrode),electroluminescence displays and LCD (e.g. interlayer insulating layer,spacers, microlens array), as composition for encapsulating electricaland electronic components, for producing magnetic recording materials,micromechanical parts, waveguides, optical switches, plating masks, etchmasks, colour proofing systems, glass fibre cable coatings, screenprinting stencils, for producing three-dimensional objects by means ofstereolithography, and as image recording material, especially forholographic recordings, microelectronic circuits, decolorizingmaterials, decolorizing materials for image recording materials, forimage recording materials using microcapsules.

Substrates used for photographic information recordings include, forexample, films of polyester, cellulose acetate or polymer-coated papers;substrates for offset printing formes are specially treated aluminium,substrates for producing printed circuits are copper-clad laminates, andsubstrates for producing integrated circuits are, for example, siliconwafers. The layer thickness of the photosensitive layer for photographicmaterials and offset printing forms is generally from about 0.5 μm to 10μm, while for printed circuits it is from 0.1 μm to about 100 μm.Following the coating of the substrates, the solvent is removed,generally by drying, to leave a coat of the photoresist on thesubstrate.

Coating of the substrates can be carried out by applying to thesubstrate a liquid composition, a solution or a suspension. The choiceof solvents and the concentration depend principally on the type ofcomposition and on the coating technique. The solvent should be inert,i.e. it should not undergo a chemical reaction with the components andshould be able to be removed again, after coating, in the course ofdrying. Examples of suitable solvents are ketones, ethers and esters,such as methyl ethyl ketone, isobutyl methyl ketone, cyclopentanone,cyclohexanone, N-methylpyrrolidone, dioxane, tetrahydrofuran,2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol,1,2-dimethoxyethane, ethyl acetate, n-butyl acetate, ethyl3-ethoxypropionate, 2-methoxypropylacetate, methyl-3-methoxypropionate,2-heptanone, 2-pentanone, and ethyl lactate.

The solution is applied uniformly to a substrate by means of knowncoating techniques, for example by spin coating, dip coating, knifecoating, curtain coating, brushing, spraying, especially byelectrostatic spraying, and reverse-roll coating, and also by means ofelectrophoretic deposition. It is also possible to apply thephotosensitive layer to a temporary, flexible support and then to coatthe final substrate, for example a copper-dad circuit board, or a glasssubstrate by transferring the layer via lamination.

The quantity applied (coat thickness) and the nature of the substrate(layer support) are dependent on the desired field of application. Therange of coat thicknesses generally comprises values from about 0.1 μmto more than 100 μm, for example 0.1 μm to 1 cm, preferably 0.5 μm to1000 μm.

Following the coating of the substrates, the solvent is removed,generally by drying, to leave an essentially dry resist film of thephotoresist on the substrate.

The photosensitivity of the novel compositions can extend in generalfrom about 150 nm to 600 nm, for example 190-600 nm, (UV-vis region).Suitable radiation is present, for example, in sunlight or light fromartificial light sources. Consequently, a large number of very differenttypes of light sources are employed. Both point sources and arrays(“lamp carpets”) are suitable. Examples are carbon arc lamps, xenon arclamps, low-, medium-, high- and super high-pressure mercury lamps,possibly with metal halide dopes (metal-halogen lamps),microwave-stimulated metal vapour lamps, excimer lamps, superactinicfluorescent tubes, fluorescent lamps, argon incandescent lamps,electronic flashlights, photographic flood lamps, light emitting diodes(LED), electron beams and X-rays. The distance between the lamp and thesubstrate to be exposed in accordance with the invention may varydepending on the intended application and the type and output of lamp,and may be, for example, from 2 cm to 150 cm. Laser light sources, forexample excimer lasers, such as F₂ excimer lasers at 157 nm exposure,KrF excimer lasers for exposure at 248 nm and ArF excimer lasers forexposure at 193 nm are also suitable. Lasers in the visible region canalso be employed.

The term ‘imagewisd’ exposure includes both, exposure through aphotomask comprising a predetermined pattern, for example a slide, achromium mask, a stencil mask or a reticle, as well as exposure by meansof a laser or light beam, which for example is moved under computercontrol over the surface of the coated substrate and in this wayproduces an image. Suitable UV laser exposure systems for the purposeare, for example, provided by Etec and Orbotech (DP-100™ DIRECT IMAGINGSYSTEM), as well as DI-FPD, DI-2080 from PENTAX. And thecomputer-controlled irradiation can also be achieved by electron beams.It is also possible to use masks made of liquid crystals that can beaddressed pixel by pixel to generate digital images, as is, for example,described by A. Bertsch, J. Y. Jezequel, J. C. Andre in Journal ofPhotochemistry and Photobiology A: Chemistry 1997, 107, p. 275-281 andby K.-P. Nicolay in Offset Printing 1997, 6, p. 34-37.

Following the imagewise exposure of the material and prior todevelopment, it may be advantageous to carry out thermal treatment for ashort time. After the development a thermal post bake can be performedto harden the composition and to remove all traces of solvents. Thetemperatures employed are generally 50-250° C., preferably 80-220° C.;the duration of the thermal treatment is in general between 0.25 and 60minutes.

The photocurable composition may additionally be used in a process forproducing printing plates or photoresists as is described, for example,in DE 4013358. In such a process the composition is exposed for a shorttime to visible light with a wavelength of at least 400 nm, without amask, prior to, simultaneously with or following imagewise irradiation.

After the exposure and, if implemented, thermal treatment, the unexposedareas of the photosensitive coating are removed with a developer in amanner known per se.

As already mentioned, the novel compositions can be developed by aqueousalkalis or organic solvents. Particularly suitable aqueous-alkalinedeveloper solutions are aqueous solutions of tetraalkylammoniumhydroxides or of alkali metal silicates, phosphates, hydroxides andcarbonates. Minor quantities of wetting agents and/or organic solventsmay also be added, if desired, to these solutions. Examples of typicalorganic solvents, which may be added to the developer liquids in smallquantities, are cyclohexanone, 2-ethoxyethanol, toluene, acetone andmixtures of such solvents. Depending on the substrate also solvents,e.g. organic solvents, can be used as developer, or, as mentioned abovemixtures of aqueous alkalis with such solvents. Particularly usefulsolvents for solvent development include methanol, ethanol, 2-propanol,1-propanol, butanol, diacetone alcohol, ethylene glycol monomethylether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butylether, diethyleneglycol dimethyl ether, propyleneglycol monomethyl etheracetate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, n-butylacetate, benzyl alcohol, acetone, methyl ethyl ketone, cyclopentanone,cyclohexanone, 2-heptanone, 2-pentanone, epsilon-caprolactone,gamma-butylolactone, dimethylformamide, dimethylacetamide,hexamethylphosphoramide, ethyl lactate, methyl lactate,epsilon-caprolactam, and N-methyl-pyrrolidinone. Optionally, water canbe added to these solvents up to a level at which still a clear solutionis obtained and at which sufficient solubility of the unexposed areas ofthe light sensitive composition is maintained.

The invention therefore also provides a process for thephotopolymerization of compounds containing ethylenically unsaturateddouble bonds, i.e. monomeric, oligomeric or polymeric compoundscontaining at least one ethylenically unsaturated double bond, whichcomprises adding to these compounds at least one photoinitiator of theformula I, II, III or IV as described above and irradiating theresulting composition with electromagnetic radiation, in particularlight of the wavelength 150 to 600 nm, in particular 190-600 nm, withelectron beam, or with X-rays.

The invention further provides a coated substrate which is coated on atleast one surface with a composition as described above, and describes aprocess for the photographic production of relief images, in which acoated substrate is subjected to imagewise exposure and then theunexposed portions are removed with a developer. Imagewise exposure maybe effected by irradiating through a mask or by means of a laser orelectron beam as already described above. Of particular advantage inthis context is the laser beam exposure already mentioned above.

The compounds of the invention have a good thermal stability and lowvolatility, and are also suitable for photopolymerisations in thepresence of air (oxygen). Further, they cause only low yellowing in thecompositions after photopolymerization.

The examples which follow illustrate the invention in more detail. Partsand percentages are, as in the remainder of the description and in theclaims, by weight, unless stated otherwise. Where alkyl radicals havingmore than three carbon atoms are referred to without any mention ofspecific isomers, the n-isomers are meant in each case.

EXAMPLE 1 Synthesis of 1-[9-Ethyl-6-(thiophene-2-carbonyl9.H.-carbazol-3-yl]-ethanone oxime O-acetate

Het₁=thienyl,

R₁=CH₃, R=CH₃

1.a 1-[9-Ethyl-6-thiophene-2-carbonyl)-9.H.-carbazol-3-yl]-ethanone

To N-ethylcarbazole (5.0 g; 25.6 mmol) in CH₂Cl₂ (40 ml) are added2-thenoyl chloride (thiophen-2-carbonylchloride) (3.75 g; 25.6 mmol) andAlCl₃ (3.40 g; 25.6 mmol). After stirring for 4 h at room temperature,acetyl chloride (2.0 g; 25.6 mmol) and AlCl₃ (3.4 g; 25.6 mmol) areadded. This reaction mixture is stirred at room temperature overnight.Then, the reaction mixture is poured into icewater. The products areextracted with CH₂Cl₂. The CH₂Cl₂ layer is washed with H₂O, saturatedNaHCO₃ aq. solution and with brine, followed by drying over anhydrousMgSO₄. Condensation under reduced pressure affords a gray solid (9.26 g,crude product).

The structure is confirmed by the ¹H-NMR spectrum (CDCl₃). δ [ppm]: 1.50(t, 3H), 2.73 (s, 3H), 4.45 (q, 2H), 7.22 (td, 1H), 7.50 (dd, 2H), 7.75(m, 2H), 8.15 (dd, 2H), 8.80 (dd, 2H). This solid is used for nextreaction without further purification.

1.b 1-[9-Ethyl-thiophene-2-carbonyl)-9.H.-carbazol-3-yl]-ethanone oxime

To hydroxylammonium chloride (0.72 g; 10.4 mmol) and sodium acetate(0.85 g; 10.4 mmol) dissolved in H₂O (7.5 ml) is added1-[9-Ethyl-6-(thiophene-2-carbonyl)-9.H.-carbazolyl-3-yl]-ethanone (3.0g; 8.6 mmol) in N,N-Dimethylacetamide (DMA) (15 ml). After heating for 4h, H₂O is added to the reaction mixture, the resulting yellow solid isfiltered off, washed with H₂O and dissolved in CH₂Cl₂. After drying thisCH₂Cl₂ solution over anhydrous MgSO₄, condensation under reducedpressure affords 3.02 g of a brownish yellow solid. Then reprecipitationand column chromatography afford a yellow solid. (1.5 g; 48%)

The structure is confirmed by the ¹H-NMR spectrum (CDCl₃), δ [ppm]: 1.49(t, 3H), 2.41 (s, 3H), 4.43 (q, 2H), 7.21 (td, 1H), 7.48 (q, 2H), 7.75(m, 2H), 7.87 (dd, 2H), 8.13 (dd, 1H), 8.39 (d, 1H), 8.71 (d, 1H). Thissolid is used for next reaction without further purification.

1c 1-[9-Ethyl-6-(thiophene-2-carbonyl-9.H.-carbazol-3-yl]-ethanone oximeO-acetate

1-[9-Ethyl-6-(thiophene-2-carbonyl)-9.H.-carbazol-3-yl]-ethanone oxime(1.5 g; 4.14 mmol) is dissolved in 25 ml of tetrahydrofurane (THF). Tothis solution, triethylamine (0.5 g, 5.0 mmol) is added and acetylchloride (0.4 g, 5.0 mmol) is added dropwise at 10° C. After stirring atroom temperature for 3 h, the reaction mixture is poured into H₂O, andthe products are extracted with ethyl acetate. The organic layer iswashed with saturated NaHCO₃ aq. solution and then with brine, followedby drying over anhydrous MgSO₄. After condensation, purification byrecrystallization with CH₂Cl₂— tert-Butylmethylether (TBME) (1:50) aseluent affords a pale orange solid (1.289; 76.6%).

¹H-NMR (CDCl₃). δ [ppm]: 1.44 (t, 3H), 2.25 (s, 3H), 2.48 (s, 3H), 4.39(q, 2H), 7.18 (td, 1H), 7.44 (q, 2H), 7.70 (m, 2H), 7.95 (dd, 1H), 8.08(dd, 1H), 8.46 (d, 1H), 8.68 (d, 1H).

EXAMPLES 2-29

The compounds of examples 2-29 are prepared according to the methoddescribed in example 1 from the corresponding aldehydes or ketones. Thecompounds and ¹H-NMR-data are given in tables 1-11. TABLE 1

State/mp [° C.] Example Het₁ Ar₂ R₁ R₂ ¹H-NMR δ [ppm] 2

CH₃ CH₃ — 3

Phenyl n-C₇H₁₅ — 4

OCH₃

— 5

CH₃ H — 6

CH₃ n-C₇H₁₅ liquid 0.87 (t, 3H) 1.23-1.60 (m, 10H) 2.27 (s, 3H) 2.84 (t,2H) 7.10-7.84 (m, 10H) 7

CH₃ n-C₆H₁₃ 62-65 0.80-0.89 (m, 6H) 1.23-1.60 (m, 8H) 2.26 (s, 3H) 2.82(t, 2H) 4.43 (q, 2H) 7.21-8.88 (m, 9H) 8

CH₃ CH₃ — 9

CH₃ CH₃ — 10

CH₃ n-C₆H₁₃ liquid 0.80 (t, 3H) 1.23-1.60 (m, 8H) 2.26 (s, 3H) 2.79 (t,2H) 7.17 (td, 1H) 7.39 (dd, 2H) 7.53 (dd, 2H) 7.66 (dt, 1H) 7.75 (dt,1H) 7.86 (dd, 2H) 7.20 (dd, 2H)

TABLE 2

State/mp [° C.] Ex. Ar₁′ Het₂ R₁ R₂ ¹H-NMR δ [ppm] 11

CH₃ CH₃ 141-143 0.88 (t, 3H) 2.27 (s, 3H) 2.83 (t, 2H) 7.34 (d, 2H) 7.48(m, 4H) 7.59 (m, 1H) 7.72 (m, 4H) 7.78 (dd, 2H) 12

CH₃ n-C₆H₁₃ — 13

CH₃ CH₃ liquid 1.43 (t, 3H) 2.27-2.40 (m, 9H) 4.48 (q, 2H) 6.72-7.63 (m,6H) 14

CH₃ CH₃ — 15

CH₃ Phenyl — 16

Phenyl CH₃ —

TABLE 3

State/mp [° C.] Example Het₁ Het₂ R₁ R₂ ¹H-NMR δ [ppm] 17

CH₃ CH₃ 139-140 0.94 (t, 3H) 1.34 (dt, 2H) 1.83 (tt, 2H) 2.23 (s, 3H)2.38 (s, 3H) 4.15 (t, 2H) 7.18 (d, 1H) 7.42 (d, 1H) 7.48 (s, 1H) 7.67(d, 1H) 7.82 (d, 1H) 7.90 (d, 1H) 9.00 (d, 1H) 18

CH₃ CH₃ —

TABLE 4

Example Ar₁ Het₂ R₁ M 19

CH₃ n-C₃H₆

TABLE 5

Example Het₁ Ar₂ R₁ M 20

CH₃ n-C₇H₁₄ 21

CH₃ n-C₃H₆

TABLE 6

Example Het₁ Het₂ R₁ M 22

Phenyl n-C₃H₆

TABLE 7

Example Het₁ Ar₂ Ar₁ R₁ M 23

CH₃ n-C₃H₆

TABLE 8

Example Ar₁′ Het₂ Ar₁ R₁ M 24

CH₃ n-C₃H₆

TABLE 9

Example Het₁ Het₂ Ar₁ R₁ M 25

CH₃ n-C₃H₆

TABLE 10

Example Het₂ Het₂′ R₁ R₂ R₂′ 26

CH₃ CH₃ CH₃ 27

CH₃ CH₃ CH₃

TABLE 11

Example Het₂ Ar₂ R₁ R₂ R₂′ 28

CH₃ CH₃ n-C₈H₁₃ 29

CH₃ CH₃ CH₃

EXAMPLE 30 30.1: Preparation of Poly(benzylmethacrylate-co-methacrylicacid)

24 g of benzylmethacrylate, 6 g of methacrylic acid and 0.525 g ofazobisisobutyronitrile (AIBN) are dissolved in 90 ml of propylene glycol1-monomethyl ether 2-acetate (PGMEA). The resulting reaction mixture isplaced in a preheated oil bath at 80° C. After stirring for 5 hours at80° C. under nitrogen, the resulting viscous solution is cooled to roomtemperature and used without further purification. The solid content isabout 25%.

30.2: Sensitivity Tests

A photocurable composition for a sensitivity test is prepared by mixingthe following components:

-   -   200.0 parts by weight of copolymer of benzylmethacrylate and        methacrylic acid (benzylmethacrylate:methacrylic acid=80:20 by        weight) 25% propylene glycol 1-monomethyl ether 2-acetate        (PGMEA) solution, prepared as described above    -   50.0 parts by weight of dipentaerythritol hexaacrylate ((DPHA),        provided by UCB Chemicals),    -   2.0 parts by weight of photoinitiator, and    -   150.0 parts by weight of PGMEA.

All operations are carried out under yellow light. The compositions areapplied to an aluminum plate using an electric applicator with a wirewound bar. The solvent is removed by heating at 100° C. for 2 minutes ina convection oven. The thickness of the dry film is approximately 2 μm.A standardized test negative film with 21 steps of different opticaldensity (Stouffer step wedge) is placed with an air gap of around 100 μmbetween the film and the resist. Exposure is carried out using a 250 Wsuper high pressure mercury lamp (USHIO, USH-250BY) at a distance of 15cm. A total exposure dose measured by an optical power meter (ORC UVLight Measure Model UV-M02 with UV-35 detector) on the test negativefilm is 1000 mJ/cm². After exposure, the exposed film is developed with1% sodium carbonate aqueous solution for 100 sec. at 30° C. by using aspray type developer (Walter Lemmen, model T21). The sensitivity of theinitiator system used is characterized by indicating the highest numberof the step remained (i.e. polymerized) after developing. The higher thenumber of steps, the more sensitive is the system tested. The resultsare listed in table 12. TABLE 12 Compound Number of steps reproducedafter of example exposure of 1000 mJ/cm² 1 20 6 15 7 16 10 17 11 16 1718

EXAMPLE 31

A photocurable formulation for a sensitivity test is prepared by mixingthe following components:

-   -   200.0 part by weight of acrylated acrylcopolymer (ACA200M,        provided by Daicel Industries, Ltd., solid content is 50% by        weight)    -   15.0 parts by weight of dipentaerythritol hexaacrylate ((DPHA),        provided by UCB Chemicals),    -   100.0 parts by weight of acetone

To that mixture 0.5% (based on the solid content) ofisopropylthioxanthone (®™QUANTACURE ITX, provided by InternationalBiosynthetics) and 2% (based on the solid content) of the initiator tobe tested are added and stirred. All operations are carried out underyellow light. The formulations are applied to an aluminum plate. Thesolvent is removed by heating at 80° C. for 15 minutes in a convectionoven. The thickness of the dry film is 25 μm. To this coating an acetatefilm is applied, over which a standardized test negative with 21 stepsof different optical density (Stouffer step wedge) is placed. The sampleis covered with a second UV-transparent film and pressed onto a metalplate by means of vacuum. Exposure is carried out in a first series for40 seconds, in a second series for 80 seconds and in a third series for160 seconds, using a metal halide lamp (ORC, model SMX 3000) at adistance of 60 cm. Following exposure, the cover films and the mask areremoved and the exposed film is developed with 1% sodium carbonateaqueous solution for 180 sec. at 30° C. by using a spray type developer(Walter Lemmen, model T21). The sensitivity of the initiator system usedis characterized by indicating the highest step number which remained(i.e. polymerized) after developing. The higher the number of steps, themore sensitive is the system tested. The results are collected in table13. TABLE 13 Number of steps reproduced Photoinitiator after exposuretime of of example Sensitizer 40 sec. 80 sec. 160 sec. 1 — 16 17 18 1QUANTACURE 16 17 18 ITX 7 — 12 14 16 7 QUANTACURE 12 14 15 ITX 10 — 1316 17 10 QUANTACURE 13 15 16 ITX 17 — 12 15 16 17 QUANTACURE 13 15 16ITX

1. Compounds of the formula I, II, III and IV

Het₁ is furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,oxazolyl, isoxazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, benzothiadiazolyl,2- or 3-indolyl, indazolyl, quinolyl, isoquinolyl, phthalazinyl,quinoxalinyl, pteridinyl, or bithienyl; each of which is unsubstitutedor substituted 1 to 7 times by halogen, C₁-C₁₂alkyl, C₃-C₈cycloalkyl,benzyl and/or phenoxycarbonyl; or each of which is substituted by phenylor by phenyl which is optionally substituted by one or more OR₃, SR₄and/or NR₅R₈; or each of which is substituted by C₂-C₁₂alkoxycarbonyl,which optionally is interrupted by one or more —O— or —S— and saidC₂-C₁₂alkoxycarbonyl optionally is substituted by one or more hydroxylgroups; or each of which is substituted by one or more OR₃, SR₄, SOR₄,SO₂R₄ and/or NR₅R₆, wherein the substituents OR₃, SR₄ or NR₅R₆optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the heteroaromatic ring; or eachof which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholinoand/or dimethylmorpholino; Het₂ and Het₂′ independently of one anotherare furylene, thienylene, pyrrolylene, imidazolylene, pyrazolylene,thiazolylene, oxazolylene, isoxazolylene, pyridylene, pyrazinylene,pyridazinylene, triazinylene, benzofurylene, benzothienylene,benzothiazolylene, benzothiadiazolylene, indolylene, indazolylen,quinolylene, isoquinolylene, phthalazinylene, quinoxalinylene,pteridinylene, bithienylene, furylenecarbonyl, thienylenecarbonyl,pyrrolylenecarbonyl, imidazolylenecarbonyl, pyrazolylene,thiazolylenecarbonyl, oxazolylenecarbonyl, pyridylenecarbonyl,pyrazinylenecarbonyl, pyridazinylenecarbonyl, triazinylenecarbonyl,benzofurylenecarbonyl, benzothienylenecarbonyl,benzothiazolylenecarbonyl, benzothiadiazolylenecarbonyl,indolylenecarbonyl, indazolylenecarbonyl, quinolylenecarbonyl,isoquinolylenecarbonyl, phthalazinylenecarbonyl,quinoxalinylenecarbonyl, pteridinylenecarbonyl or bithienylenecarbonyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄, and/orNR₅R₆; or each of which is substituted by phenyl or by naphthyl, saidphenyl or naphthyl optionally is substituted by one or more OR₃, SR₄and/or NR₅R₆; Ar₁ and Ar₁′ independently of one another are phenyl,naphthyl, benzoyl, naphthoyl, or a group

each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl; or each ofwhich is substituted by phenyl or by phenyl which is substituted by oneor more OR₃, SR₄, NR₅R₆, morpholino and/or dimethylmorpholino; or eachof which is substituted by C₂-C₁₂alkoxycarbonyl which optionally isinterrupted by one or more —O— or —S— and/or optionally is substitutedby one or more hydroxyl groups; or each of which is substituted by oneor more OR₃, SR₄, SOR₄, SO₂R₄ NR₅R₆, morpholino and/ordimethylmorpholino; or each of which is substituted by C₁-C₈alkanoyl orbenzoyl, said C₁-C₈alkanoyl or benzoyl optionally is substituted by OR₃,SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholino and/or dimethylmorpholino, whereinthe substitutents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-memberedrings via the radicals R₃, R₄, R₅ and/or R₆ with further substituents onthe phenyl ring; provided that (i) if in formula I, Ch₁ is

Ar₁′ is phenyl, Het₂ is 5-phenyl-4,3-isoxazolylene and R₂ is phenyl,then R₁ is not phenyl; Ar₂ is phenylene, naphthylene, phenylenecarbonyl,naphthylenecarbonyl, or a group

each of which is unsubstituted or substituted 1 to 6 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆; M is C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which is interrupted byone or more —O— or —S—, said C₁-C₂₀alkylene and C₂-C₂₀alkyleneoptionally is substituted by one or more halogen, OR₃, phenyl or phenylsubstituted by OR₃, SR₄ and/or NR₅R₆; or M is phenylene or naphthylene,each of which is unsubstituted or substituted by one or more C₁-C₆alkyl,phenyl, halogen, OR₃, SR₄ and/or NR₅R₆; X is a direct bond, —O—, —S—,—NR₅— or —CO—; Y is —O—, —S—, —NR₅—, —CO— or —CH₂—; R₁ is hydrogen,C₃-C₈cycloalkyl; or is C₁-C₁₂alkyl which is unsubstituted or substitutedby one or more halogen, phenyl and/or CN; or R₁ is C₂-C₅alkenyl; or isphenyl which is unsubstituted or substituted by one or more C₁-C₆alkyl,halogen, CN, OR₃, SR₄ and/or NR₅R₆; or R₁ is C₁-C₈alkoxy, benzyloxy; orphenoxy which optionally is substituted by one or more C₁-C₆alkyl and/orhalogen; R₂ and R₂′ independently of each other are hydrogen;unsubstituted C₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or morehalogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₃-C₈cycloalkyl; or are C₂-C₂₀alkyl interrupted by oneor more —O— or —S—, and/or optionally substituted by one or morehalogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are phenyl which is unsubstituted or substituted by one ormore C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′are C₂-C₂₀alkanoyl or benzoyl which is unsubstituted or substituted byone or more C₁-C₆alkyl, phenyl, OR₃, SR4 and/or NR₅R₆; or R₂ and R₂′ areC₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— or —S—and/or optionally substituted by one or more hydroxyl groups; or R₂ andR₂′ are phenoxycarbonyl which is unsubstituted or substituted byC₁-C₆alkyl, halogen, phenyl, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ areCN, —CONR₅R₆, NO₂, C₁-C₄haloalkyl, S(O)_(m)—C₁-C₆alkyl orS(O)_(m)-phenyl which is optionally substituted by C₁-C₁₂alkyl orSO₂—C₁-C₆alkyl; or R₂ and R₂′ are SO₂O-phenyl which optionally issubstituted by C₁-C₁₂alkyl; or R₂ and R₂′ are furyl, thienyl, pyrrolylor pyridyl; m is 1 or 2; R₃ is hydrogen, C₁-C₂₀alkyl orphenyl-C₁-C₃alkyl; or R₃ is C₁-C₈alkyl which is substituted by —OH, —SH,—CN, C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)—(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OH and/or —(CO)O(C₁-C₄alkyl);or R₃ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—; orR₃ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl), C₁-C₈alkanoyl,C₂-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃ is benzoyl which isunsubstituted or substituted by one or more C₁-C₆alkyl, halogen, OHand/or C₁-C₄alkoxy; or R₃ is phenyl or naphthyl each of which isunsubstituted or substituted by halogen, OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/ordiphenylamino; n is 1-20; R₄ is hydrogen, C₁-C₂₀alkyl, C₂-C₁₂alkenyl,C₃-C₈cycloalkyl or phenyl-C₁-C₃alkyl; or R₄ is C₁-C₈alkyl which issubstituted by —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN,—OCH₂CH₂(CO)O(C₁-C₄alkyl), —O(CO)—(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OHor —(CO)O(C₁-C₄alkyl); or R₄ is C₂-C₁₂alkyl which is interrupted by oneor more —O— or —S—; or R₄ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl), C₁-C₈alkanoyl, C₂-C₁₂alkenyl orC₃-C₆alkenoyl; or R₄ is benzoyl which is unsubstituted or substituted byone or more C₁-C₆alkyl, halogen, OH, C₁-C₄alkoxy or C₁-C₄alkylsulfanyl;or R₄ is phenyl or naphthyl, each of which is unsubstituted orsubstituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenyl-C₁-C₃alkyloxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂,diphenylamino, —(CO)O(C₁-C₈alkyl), —(CO)—C₁-C₈alkyl or(CO)N(C₁-C₈alkyl)₂; and R₅ and R₆ independently of each other arehydrogen, C₁-C₂₀alkyl, C₂-C₄hydroxyalkyl, C₂-C₁₀-alkoxyalkyl,C₂-C₅alkenyl, C₃-C₈cycloalkyl, phenyl-C₁-C₃alkyl, C₁-C₈alkanoyl,C₃-C₁₂alkenoyl or benzoyl; or R₅ and R₆ are phenyl or naphthyl, each ofwhich is unsubstituted or substituted by C₁-C₁₂alkyl, benzoyl orC₁-C₁₂alkoxy; or R₅ and R₆ together are C₂-C₈alkylene which optionallyis interrupted by —O—, —S— or —NR₃— and/or optionally substituted byhydroxyl, C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy.
 2. Compounds ofthe formulae I, II, III and IV according to claim 1, wherein Het₁ isfuryl, thienyl, pyrrolyl, pyridyl, pyrazinyl, pyridazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, 2- or 3-indolyl,quinolyl, isoquinolyl or quinoxalinyl; each of which is unsubstituted orsubstituted 1 to 7 times by halogen or C₁-C₁₂alkyl; or each of which issubstituted by phenyl or by phenyl which optionally is substituted byone or more OR₃, SR₄ and/or NR₅R₆; or each of which is substituted byOR₃, SR₄, SOR₄ and/or NR₅R₆, wherein the substituents OR₃, SR₄ or NR₅R₆optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the heteroaromatic ring; or eachof which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino; Het₂ and Het₂′ independently of one another arefurylene, thienylene, pyrrolylene, benzofurylene, benzothienylene,indolylene, quinolylene, isoquinolylene, quinoxalinylene,furylenecarbonyl, thienylenecarbonyl, pyrrolylenecarbonyl,benzofurylenecarbonyl, benzothienylenecarbonyl, indolylenecarbonyl,quinolylenecarbonyl, isoquinolylenecarbonyl, quinoxalinylenecarbonyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆; or each of which is substituted by phenyl or naphthyl, saidphenyl or naphthyl optionally is substituted by one or more OR₃, SR₄and/or NR₅R₆; Ar₁ and Ar₁′ independently of one another are phenyl,naphthyl or a group (B); each of which is unsubstituted or substituted 1to 7 times by halogen, C₁-C₆alkyl, OR₃, SR₄, NR₅R₆, morpholino and/ordimethylmorpholino, or each of which is substituted by benzoyl, phenylor by phenyl which is optionally substituted by one or more OR₃, SR₄,NR₅R₆, morpholino and/or dimethylmorpholino; Ar₂ is phenylene,naphthylene, phenylenecarbonyl, naphthylenecarbonyl, or a group (C),(D), (E) or (F), each of which is unsubstituted or substituted 1 to 6times by halogen, C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄,SO₂R₄ and/or NR₅R₆; M is C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which isinterrupted by one or more —O— or —S—, said C₁-C₂₀alkylene andC₂-C₂₀alkylene optionally is substituted by one or more halogen, OR₃,phenyl or phenyl substituted by OR₃, SR₄ and/or NR₅R₆; or M is phenyleneor naphthylene, each of which is unsubstituted or substituted by one ormore C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or NR₅R₆; X is a directbond or —CO—; Y is —O—, —S— or —NR₅—; R₁ is C₁-C₆alkyl which isunsubstituted or substituted by one or more halogen or phenyl; or R₁ isphenyl which is unsubstituted or substituted by one or more C₁-C₆alkyl,halogen, OR₃, SR₄ and/or NR₅R₆; or R₁ is C₁-C₆alkoxy or benzyloxy; R₂and R₂′ independently of each other are hydrogen; unsubstitutedC₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or more halogen, OR₃,phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′are C₃-C₈cycloalkyl; or are C₂-C₂₀alkyl interrupted by one or more —O—and/or optionally substituted by one or more halogen, OR₃, phenyl and/orphenyl substituted by OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ are phenylwhich is unsubstituted or substituted by one or more C₁-C₆alkyl, phenyl,halogen, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ are C₂-C₂₀alkanoyl orbenzoyl which is unsubstituted or substituted by one or more C₁-C₆alkyl,phenyl, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ are furyl, thienyl,pyrrolyl or pyridyl; R₃ is hydrogen, C₁-C₂₀alkyl or phenyl-C₁-C₃alkyl;or R₃ is C₁-C₈alkyl which is substituted by C₃-C₆alkenoxy,—O(CO)—(C₁-C₄alkyl) or —O(CO)-phenyl; or R₃ is C₂-C₁₂alkyl which isinterrupted by one or more —O—; or R₃ is C₁-C₈alkanoyl or is benzoylwhich is unsubstituted or substituted by one or more C₁-C₆alkyl, halogenand/or C₁-C₄alkoxy; or R₃ is phenyl or naphthyl each of which isunsubstituted or substituted by halogen, C₁-C₁₂alkyl, C₁-C₄alkoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/ordiphenylamino; R₄ is hydrogen, C₁-C₂₀alkyl, or is C₁-C₈alkyl which issubstituted by —O(CO)—(C₁-C₄alkyl) or —O(CO)-phenyl; or R₄ isC₂-C₁₂alkyl which is interrupted by one or more —O— or —S—; or R₄ isC₁-C₈alkanoyl; or is benzoyl which is unsubstituted or substituted byone or more C₁-C₆alkyl, C₁-C₄alkoxy or C₁-C₄alkylsulfanyl; or R₄ isphenyl or naphthyl, each of which is unsubstituted or substituted byhalogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenyl-C₁-C₃alkyloxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ or diphenylamino;and R₅ and R₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁₀-alkoxyalkyl, phenyl-C₁-C₃alkyl, C₁-C₈alkanoyl,C₃-C₁₂alkenoyl or benzoyl; or R₅ and R₆ are phenyl or naphthyl, each ofwhich is unsubstituted or substituted by C₁-C₁₂alkyl, benzoyl orC₁-C₁₂alkoxy; or R₅ and R₆ together are C₂-C₈alkylene which optionallyis interrupted by —O— or —NR₃— and/or optionally is substituted byC₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy.
 3. Compounds of the formulaI, II, III and IV according to claim 1, wherein Ch₂ is

Het₁ is furyl, thienyl, pyrrolyl, pyridyl, 2- or 3-benzothienyl or 2- or3-indolyl; each of which is unsubstituted or substituted by C₁-C₁₂alkyl;Het₂ and Het₂′ independently of one another are thienylene, pyrrolylene,benzothienylene, indolylene, indolylenecarbonyl; each of which isunsubstituted or substituted by C₁-C₁₂alkyl; Ar₁ and Ar₁′ independentlyof one another are phenyl, naphthyl or a group (B); each of which isunsubstituted or substituted by C₁-C₁₂alkyl OR₃, SR₄ or morpholino; Ar₂is a group (C), (D) or (E); each of which is unsubstituted orsubstituted by C₁-C₁₂alkyl; M is C₁-C₂₀alkylene; X is a direct bond; Yis —O—, —S— or —NR₅—; R₁ is C₁-C₁₂alkyl, phenyl or C₁-C₈alkoxy; R₂ andR₂′ independently of each other are hydrogen, C₁-C₂₀alkyl or phenyl; R₃is C₁-C₂₀alkyl; and R₄, R₅ and R₆ independently of each other areC₁-C₂₀alkyl or phenyl.
 4. Compounds of the formula I according to claim1, wherein Ch₁ is

Het₁ is 2-thienyl, 2-furyl, N—(C₁-C₄alkyl)-2-pyrrolyl,N-(phenyl)-2-pyrrolyl, 4-pyridinyl, N—(C₁-C₄alkyl)-3-indolyl orN-(phenyl)-3-indolyl; Het₂ is 2,5-thienylene, 2,5-furylene,N—(C₁-C₄alkyl)-2,5-pyrrolylene, N-(phenyl)-2,5-pyrrolylene,N—(C₁-C₄alkyl)-indolylene, N—(C₁-C₄alkyl)-indolylenecarbonyl,5-thienylene-2-carbonyl, 5-furylene-2-carbonyl orN—(C₁-C₄alkyl)-5-pyrrolylene-2-carbonyl orN-(phenyl)-5-pyrrolylene-2-carbonyl; Ar₁ and Ar₁′ independently of oneanother are phenyl, naphthyl or a group (B); each of which isunsubstituted or substituted by 1 to 7 times by C₁-C₆alkyl, benzoyl,OR₃, SR₄, NR₅R₆, morpholino and/or dimethylmorpholino; Ar₂ is phenylene,phenylenecarbonyl, or a group (C), (D), (E) or (F), each of which isunsubstituted or substituted by 1 to 7 times by C₁-C₆alkyl, OR₃, SR₄ orNR₅R₆; X is a direct bond or —CO—; Y is —S— or —NR₅—; R₁ is C₁-C₃alkyl,phenyl or C₁-C₄alkoxy; R₂ is hydrogen, C₁-C₈alkyl or phenyl; R₃ isC₁-C₁₂alkyl; R₄ is C₁-C₁₂alkyl or phenyl; and R₅ and R₆ independently ofeach other are C₁-C₁₂alkyl or phenyl.
 5. A photopolymerizablecomposition comprising (a) at least one ethylenically unsaturatedphotopolymerizable compound, and (b) as photoinitiator, at least onecompound selected from the group consisting of the formula I, II, IIIand IV

Het₁ is furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,oxazolyl, isoxazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, 2- or3-benzofuryl, 2- or 3-benzothienyl, benzothiazolyl, benzothiadiazolyl,2- or 3-indolyl, indazolyl, quinolyl, isoquinolyl, phthalazinyl,quinoxalinyl, pteridinyl, or bithienyl; each of which is unsubstitutedor substituted 1 to 7 times by halogen, C₁-C₁₂alkyl, C₃-C₈cycloalkyl,benzyl and/or phenoxycarbonyl; or each of which is substituted by phenylor by phenyl which is optionally substituted by one or more OR₃, SR₄and/or NR₅R₆; or each of which is substituted by C₂-C₁₂alkoxycarbonyl,which optionally is interrupted by one or more —O— or —S— and saidC₂-C₁₂alkoxycarbonyl optionally is substituted by one or more hydroxylgroups; or each of which is substituted by one or more OR₃, SR₄, SOR₄,SO₂R₄ and/or NR₅R₆, wherein the substituents OR₃, SR₄ or NR₅R₆optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the heteroaromatic ring; or eachof which is substituted by C₁-C₈alkanoyl or benzoyl, which isunsubstituted or substituted by OR₃, SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholinoand/or dimethylmorpholino; Het₂ and Het₂′ independently of one anotherare furylene, thienylene, pyrrolylene, imidazolylene, pyrazolylene,thiazolylene, oxazolylene, isoxazolylene, pyridylene, pyrazinylene,pyridazinylene, triazinylene, benzofurylene, benzothienylene,benzothiazolylene, benzothiadiazolylene, indolylene, indazolylen,quinolylene, isoquinolylene, phthalazinylene, quinoxalinylene,pteridinylene, bithienylene, furylenecarbonyl, thienylenecarbonyl,pyrrolylenecarbonyl, imidazolylenecarbonyl, pyrazolylene,thiazolylenecarbonyl, oxazolylenecarbonyl, pyridylenecarbonyl,pyrazinylenecarbonyl, pyridazinylenecarbonyl, triazinylenecarbonyl,benzofurylenecarbonyl, benzothienylenecarbonyl,benzothiazolylenecarbonyl, benzothiadiazolylenecarbonyl,indolylenecarbonyl, indazolylenecarbonyl, quinolylenecarbonyl,isoquinolylenecarbonyl, phthalazinylenecarbonyl,quinoxalinylenecarbonyl, pteridinylenecarbonyl or bithienylenecarbonyl;each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄, and/orNR₅R₆; or each of which is substituted by phenyl or by naphthyl, saidphenyl or naphthyl optionally is substituted by one or more OR₃, SR₄and/or NR₅R₆; Ar₁ and Ar₁′ independently of one another are phenyl,naphthyl, benzoyl, naphthoyl, or a group

each of which is unsubstituted or substituted 1 to 7 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl and/or phenoxycarbonyl; or each ofwhich is substituted by phenyl or by phenyl which is substituted by oneor more OR₃, SR₄, NR₅R₆, morpholino and/or dimethylmorpholino; or eachof which is substituted by C₂-C₁₂alkoxycarbonyl which optionally isinterrupted by one or more —O— or —S— and/or optionally is substitutedby one or more hydroxyl groups; or each of which is substituted by oneor more OR₃, SR₄, SOR₄, SO₂R₄ NR₅R₆, morpholino and/ordimethylmorpholino; or each of which is substituted by C₁-C₈alkanoyl orbenzoyl, said C₁-C₈alkanoyl or benzoyl optionally is substituted by OR₃,SR₄, SOR₄, SO₂R₄, NR₅R₆, morpholino and/or dimethylmorpholino, whereinthe substitutents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-memberedrings via the radicals R₃, R₄, R₅ and/or R₆ with further substituents onthe phenyl ring; provided that (i) if in formula I, Ch₁ is

Ar₁′ is phenyl, Het₂ is 5-phenyl-4,3-isoxazolylene and R₂ is phenyl,then R₁ is not phenyl; and (ii) if, in formula I, Ch₁ is

Het₁ is 2-thienyl and R₂ is phenyl, then R₁ is not phenyl; Ar₂ isphenylene, naphthylene, phenylenecarbonyl, naphthylenecarbonyl, or agroup

each of which is unsubstituted or substituted 1 to 6 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ and/orNR₅R₆; M is C₁-C₂₀alkylene or is C₂-C₂₀alkylene, which is interrupted byone or more —O— or —S—, said C₁-C₂₀alkylene and C₂-C₂₀alkyleneoptionally is substituted by one or more halogen, OR₃, phenyl or phenylsubstituted by OR₃, SR₄ and/or NR₅R; or M is phenylene or naphthylene,each of which is unsubstituted or substituted by one or more C₁-C₆alkyl,phenyl, halogen, OR₃, SR₄ and/or NR₅R₆; X is a direct bond, —O—, —S—,—NR₅— or —CO—; Y is —O—, —S—, —NR₅—, —CO— or —CH₂—; R₁ is hydrogen,C₃-C₈cycloalkyl; or is C₁-C₁₂alkyl which is unsubstituted or substitutedby one or more halogen, phenyl and/or CN; or R₁ is C₂-C₅alkenyl; or isphenyl which is unsubstituted or substituted by one or more C₁-C₆alkyl,halogen, CN, OR₃, SR₄ and/or NR₅R₆; or R₁ is C₁-C₈alkoxy, benzyloxy; orphenoxy which optionally is substituted by one or more C₁-C₆alkyl and/orhalogen; R₂ and R₂′ independently of each other are hydrogen;unsubstituted C₁-C₂₀alkyl or C₁-C₂₀alkyl substituted by one or morehalogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are C₃-C₈cycloalkyl; or are C₂-C₂₀alkyl interrupted by oneor more —O— or —S—, and/or optionally substituted by one or morehalogen, OR₃, phenyl and/or phenyl substituted by OR₃, SR₄ and/or NR₅R₆;or R₂ and R₂′ are phenyl which is unsubstituted or substituted by one ormore C₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′are C₂-C₂₀alkanoyl or benzoyl which is unsubstituted or substituted byone or more C₁-C₆alkyl, phenyl, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ areC₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— or —S—and/or optionally substituted by one or more hydroxyl groups; or R₂ andR₂′ are phenoxycarbonyl which is unsubstituted or substituted byC₁-C₆alkyl, halogen, phenyl, OR₃, SR₄ and/or NR₅R₆; or R₂ and R₂′ areCN, —CONR₅R₆, NO₂, C₁-C₄haloalkyl, S(O)_(m)—C₁-C₆alkyl orS(O)_(m)-phenyl which is optionally substituted by C₁-C₁₂alkyl orSO₂—C₁-C₆alkyl; or R₂ and R₂′ are SO₂O-phenyl which optionally issubstituted by C₁-C₁₂alkyl; or R₂ and R₂′ are furyl, thienyl, pyrrolylor pyridyl; m is 1 or 2; R₃ is hydrogen, C₁-C₂₀alkyl orphenyl-C₁-C₃alkyl; or R₃ is C₁-C₈alkyl which is substituted by —OH, —SH,—CN, C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)—(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OH and/or —(CO)O(C₁-C₄alkyl);or R₃ is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—; orR₃ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl), C₁-C₈alkanoyl,C₂-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃ is benzoyl which isunsubstituted or substituted by one or more C₁-C₆alkyl, halogen, OHand/or C₁-C₄alkoxy; or R₃ is phenyl or naphthyl each of which isunsubstituted or substituted by halogen, OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ and/ordiphenylamino; n is 1-20; R₄ is hydrogen, C₁-C₂₀alkyl, C₂-C₁₂alkenyl,C₃-C₈cycloalkyl or phenyl-C₁-C₃alkyl; or R₄ is C₁-C₈alkyl which issubstituted by —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN,—OCH₂CH₂(CO)O(C₁-C₄alkyl), —O(CO)—(C₁-C₄alkyl), —O(CO)-phenyl, —(CO)OHor —(CO)O(C₁-C₄alkyl); or R₄ is C₂-C₁₂alkyl which is interrupted by oneor more —O— or —S—; or R₄ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)—(C₁-C₈alkyl), C₁-C₈alkanoyl, C₂-C₁₂alkenyl orC₃-C₆alkenoyl; or R₄ is benzoyl which is unsubstituted or substituted byone or more C₁-C₆alkyl, halogen, OH, C₁-C₄alkoxy or C₁-C₄alkylsulfanyl;or R₄ is phenyl or naphthyl, each of which is unsubstituted orsubstituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenyl-C₁-C₃alkyloxy,phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂,diphenylamino, —(CO)O(C₁-C₈alkyl), —(CO)—C₁-C₈alkyl or(CO)N(C₁-C₈alkyl)₂; and R₅ and R₆ independently of each other arehydrogen, C₁-C₂₀alkyl, C₂-C₄hydroxyalkyl, C₂-C₁₀-alkoxyalkyl,C₂-C₅alkenyl, C₃-C₈cycloalkyl, phenyl-C₁-C₃alkyl, C₁-C₈alkanoyl,C₃-C₁₂alkenoyl or benzoyl; or R₅ and R₆ are phenyl or naphthyl, each ofwhich is unsubstituted or substituted by C₁-C₁₂alkyl, benzoyl orC₁-C₁₂alkoxy; or R₅ and R₆ together are C₂-C₈alkylene which optionallyis interrupted by —O—, —S— or —NR₃— and/or optionally substituted byhydroxyl, C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy.
 6. Aphotopolymerizable composition according to claim 5 comprising ascomponent (a) a compound having at least two ethylenically unsaturatedbonds and at least one carboxylic acid group.
 7. A photopolymerizablecomposition according to claim 5 comprising in addition to thephotoinitiator (b) at least one further photoinitiator (c) and/or otheradditives (d).
 8. A photopolymerizable composition according to claim 5,comprising 0.05 to 25% by weight of the photoinitiator (b), or thephotoinitiators (b) and (c), based on the composition.
 9. Aphotopolymerizable composition according to claim 8, comprising as afurther additive (d) a photosensitizer.
 10. A photopolymerizablecomposition according to claim 5 additionally comprising a binderpolymer (e).
 11. A process for the photopolymerization of compoundscontaining ethylenically unsaturated double bonds, which comprisesirradiating a composition according to of claim 5 with electromagneticradiation in the range from 150 to 600 nm, or with electron beam or withX-rays.
 12. (canceled)
 13. A process according to claim 11 for producingpigmented and non-pigmented paints and varnishes, powder coatings,printing inks, printing plates, adhesives, dental compositions, puttymaterials, gel coats, photoresists for electronics like electroplatingresist, etch resist, both liquid and dry films, solder resist, asresists to manufacture color filters and spacers for a variety ofdisplay applications or to generate structures in the manufacturingprocesses of plasma-display panels, electroluminescence displays andLCDs, composite compositions, resists, including photoresists, colorfilter materials, compositions for encapsulating electrical andelectronic components, for producing magnetic recording materials,micromechanical parts, waveguides, optical switches, plating masks, etchmasks, colour proofing systems, glass fibre cable coatings, screenprinting stencils, for producing three-dimensional objects by means ofmicrolithography, plating, stereolithography, for producing imagerecording materials, especially for holographic recordings,microelectronic circuits, decolorizing materials for image recordingmaterials using microcapsules, for forming dielectric layers in asequential build-up layer of a printed circuit board.
 14. A coatedsubstrate which is coated on at least one surface with a compositionaccording to claim
 5. 15. Process for the photographic production ofrelief images, in which a coated substrate according to claim 14 issubjected to imagewise exposure and then the unexposed portions areremoved with a developer.
 16. A color filter prepared by providing red,green and blue picture elements and a black matrix, all comprising aphotosensitive resin and a pigment on a transparent substrate andproviding a transparent electrode either on the surface of the substrateor on the surface of the color filter layer, wherein said photosensitiveresin comprises a polyfunctional acrylate monomer, an organic polymerbinder and at least one photopolymerization initiator selected from thegroup consisting of formula I, II III and IV according to claim
 1. 17. Aphotopolymerizable composition according to claim 9, wherein furtheradditive (d) is a photosensitizer compound selected from the groupconsisting of benzophenone and its derivatives, thioxanthone and itsderivatives, anthraquinone and its derivatives, and coumarin and itsderivatives.
 18. A photopolymerizable composition according to claim 5additionally comprising as a binder polymer (e) a copolymer ofmethacrylate and methacrylic acid.
 19. A process according to claim 13using UV and visible laser as a light source of a direct imagingtechnique.
 20. A process according to claim 11, wherein the compositionbeing photpolymerised comprises 0.05 to 25% by weight of thephotoinitiator (b), or the photoinitiators (b) and (c), based on thecomposition.
 21. A process according to claim 11, wherein thecomposition being photpolymerised further comprises a photosensitizer.